Question: Why is is Yoda is always seen stooped and hobbling around everywhere with a walking stick - but when it comes to fighting, with his duel against Count Dooku at the end of this movie for example - he all of a sudden practically becomes a ninja; jumping, spinning and battling with his lightsaber so spectacularly?
Question: How old is Anakin in this movie, at least when he and Padme get married at the end (depending on how much time passes throughout the movie)? I've read both eighteen and twenty.
Answer: Anakin was born in 42BBY and the events of the film take place in 22BBY, making Anakin nineteen or twenty when he marries, depending on precisely when it occurred in the year.
Tailkinker
Question: Is it true that Keira Knightly almost played Padme in this movie and Episode III, because Natalie Portman didn't want to do it anymore?
Answer: No. All the main actors were contractually obliged to do all three prequel movies.
GalahadFairlightQuestion: Did Dooku have any personal reason for wanting to kill Padme, or did he just send Jango after her as a favor to Nute Gunray?
Answer: Gunray demanded that Amidala be targeted as part of his price to bring the Trade Federation, with its substantial military force, into the Seperatist movement.
Tailkinker Question: During Anakin's duel with Dooku, why did he cut that huge cable and why exactly did he open himself up by sticking his arm out, thus giving Dooku the opportunity to chop it off?
Socks1000Chosen answer: He presumably cut it so he wouldn't trip over it. Dooku was a better fighter than him and Anakin was overconfident, but Dooku was one of the top duelists in the entire order. His style was meant for saber-to-saber combat, whereas Anakin's was meant to block blaster bolts. He lost his arm because he didn't think.
Question: On the Wookiepedia/Star Wars Wiki articles for Sidious, it has his age as 20 years younger than Dooku. Does Dooku really listen to someone young enough to be his son?
Answer: That's the master/apprentice mentality. It doesn't matter how old they are. The master has more experience (in this case, in the dark side) and can teach the apprentice. The apprentice needs to learn their place in the relationship in order to be a good vessel for the knowledge they seek.
Garlonuss Question: Dooku mentions that his and Obi-wan's paths have never crossed before. Does he mean that they have never met at all, or just not since Dooku left the order? Obi-wan was 20-something years old in Episode I, when Dooku was still a Jedi, so could they really have never met each other in that many years (especially with the connection of Dooku being Obi-wan's master's master?)
Answer: It's certainly entirely plausible that their paths have not crossed previously. Jinn and Kenobi spent the vast majority of their time together away from the Jedi Temple on various missions for the Council. Dooku, for his part, had become withdrawn and dissatisfied with the Jedi Order after a couple of politically-motivated battles that he felt the Jedi should not have involved themselves with and spent much of his time meditating and discussing his concerns with other Jedi Masters. As such, the pair would only rarely have been in the same star system, making it not remotely impossible that they never met, even with their shared connection with Qui-Gon. With that in mind, it seems likely that Dooku is speaking literally and this is their first meeting.
Tailkinker Question: Why exactly did Dooku join Sidious, when Sidious was actually involved in Qui-gon's death (since his last apprentice killed Qui-gon)? Does he not really care?
Answer: Allowing nebulous emotions like caring to influence their actions is not generally part of the Sith game plan. Dooku joined up with Sidious after becoming increasingly dissatisfied with the Jedi Order and their allegiance to a Senate that he saw as fatally corrupted. After a couple of disastrous battles, which Dooku learned the Jedi had been manipulated into fighting by unscrupulous politicians seeking to advance their personal agendas, he refused to accept any further missions from the Council, becoming increasingly withdrawn and concerned about the course the galaxy was following. It seems that Palpatine first met with him at around this time, some years prior to the battle of Naboo, using their meetings to determine Dooku's suitability for recruitment and gradually bringing the disaffected Jedi into his circle, much as he would do with Dooku's eventual replacement Anakin Skywalker years later. After Qui-Gon's death on Naboo in what seemed to be yet another politically motivated battle, Dooku spoke out, publically denouncing the Senate, then resigned from the Jedi Order, returning to his home planet of Serenno and reclaiming his family title of Count. Shortly after that, Palpatine approached him, revealing himself as a Sith Lord. In a long discussion, Dooku realised that Palpatine's goal of bringing the galaxy under the control of a single powerful individual, rather than the corrupt and inefficient Senate, was not far removed from his own thoughts on how things should be. Accepting Qui-Gon's death as a regrettable but necessary sacrifice to bring order to the galaxy, he agreed to join Palpatine and become his new apprentice.
Tailkinker Chosen answer: They hate the moisture farmers, who they regard as having encroached on their territory. They kidnapped Shmi and tortured her to gather information for a future big raid on the local moisture farms.
Tailkinker Question: Why did Jango Fett kill Zam Wesell with a Kamino saberdart? Surely a bounty hunter as experienced as Jango would have realised it would lead to the Kaminoans and eventually to himself? Instead, why not kill her with a well aimed laser blast?
LazyBoy09Chosen answer: At the range we're talking about, even as good a shot as Fett couldn't guarantee a kill. But hit Wesell anywhere with the poisoned dart and it does the job. Kamino's been wiped from the Archives, there's no information on the dart there either, so he probably felt that it was pretty safe to use. He couldn't have anticipated that Kenobi would have had a contact who actually could identify one. Even if they do track him down, he's a bounty hunter, which is a legal profession. Somebody with his resources would have no problem faking documentation to show that he had been contracted to take Wesell out.
Tailkinker Question: This goes along with the question someone submitted about Jedi reproducing. Isn't it also very likely that in a whole galaxy, there would be at least a few people born every year who are Force-sensitive, but aren't ever discovered by the Jedi? Couldn't the trait sometimes be passed down for a couple of generations before someone in the family is discovered by the Jedi? For example, it seems unlikely that either of Dooku's parents or Palpatine's parents were Jedi, since they both came from wealthy backgrounds.
Answer: Yes, extremely likely, particularly out on the Rim. There will always be people who either escape notice completely or, while recognised as being Force-sensitive, do not have the power level required to become a Jedi and thus would not be brought into the Order. In such cases, the Jedi would likely keep an eye on them, in case the trait manifested more strongly in any children who could then become Jedi.
Tailkinker Question: In the meeting at the beginning, after Padme is attacked, Mace says that their intelligence believes that angry spice-miners attacked her. Why do their intelligence people think that?
Answer: Presumably there's been some disquiet among the spice-miners for some reason - better working conditions, better pay, could be a lot of things. Apparently the intelligence services feel that things have got heated enough that the spice-miners might try open rebellion by attempting to assassinate their Senator.
Tailkinker Question: When Dooku and Obi-wan are fighting, Dooku says that Yoda holds Obi-wan in such high esteem. But how would he know that if he left the Jedi Order years ago and probably hasn't been talking to Yoda for a while?
Answer: Though not stated in the films, Dooku had been a member of the Jedi Order until sometime after Qui-Gon Jin's death. But probably also after Obi-Wan was given the title of Jedi Knight and Anakin his Padawan by Yoda. So Dooku could very well have known Yoda's feelings of esteem, even if it was years ago.
JC FernandezThat whole conversation between Obi-Wan and Dooku is also part of Dooku's fighting style. He was deliberately trying to get into Obi-Wan's head and get at his ego, so as to get him to loose his cool or try something brash in order to "show up" Dooku, etc. He didn't therefore need to actually know if Yoda held Obi-Wan in high esteem, he was just saying it in order to try and goad Obi-Wan into living up that "praise" and thus make a mistake; whether he was telling the truth was irrelevant.
Question: After Dooku leaves the fight with Yoda on Geonosis and Padmé arrives, are Obi-wan and Yoda not suspicious about her running to Anakin and hugging and kissing him? Yoda is actually looking in their direction.
Answer: Considering everything that just happened and that Padme has known Anakin since he was a small boy, they probably would not think that much of it other than she is very emotional and is showing concern and relief for an old friend and protector after a particularly stressful situation.
raywest Question: Obi-Wan says that it's impossible for anyone to alter the information in the star system library. How, then, could it be possible that a Jedi erased this information, as Yoda says?
Answer: What Obi-wan says is "Who could empty information from the archives? That's impossible, isn't it?" It's a question, not a statement. He's heard that it's supposed to be impossible, but the fact of the missing information clearly contradicts that. Yoda puts him straight, telling him that only a Jedi (i.e. somebody on the inside) could have done it.
Tailkinker Question: Do the Jedi know that Count Dooku is called Darth Tyranus? They continue calling him Dooku, but in the later movies, Obi-wan and Yoda considered Anakin to be "dead" and wouldn't think of Darth Vader as being the same person as Anakin.
Answer: No, they don't. At the beginning of this film they don't even realise that he's a Sith - they shoot down the idea of Dooku instigating the assassination attempt on Senator Amidala, describing him as a political idealist. While Obi-wan hears the name Tyranus from Jango Fett, he has no way to connect that name to Dooku. While they become aware of his connections to the Sith, there's no indication that they ever learn his Sith title, so they continue to use his normal name.
Tailkinker Question: During Dooku's meeting with the other Separatists on Geonosis, why does one of the Separatists say, "The techno-union army," and then stop and make that weird noise?
Answer: If I remember correctly, the Separatist in question is of a species whose vocal functions are incapable of making any sound resembling what we would call "human" speech. He wears a device that translates his sounds into a more discernible language. It needed an adjustment at this point, and you can even see him reach up and turn a knob.
Phixius Question: After Mace kills Jango, why does he stare at him for a moment? He is too far away to have seen the look on Dooku's face.
Answer: In the novelization for Episode III it explains that mace Windu created a fighting style known a Vaapad. It also explains that this form of fighting is very dangerous because the user's mind becomes passive. It is possible that Mace Windu was only then realizing that he had killed Jango.
Question: After Jar-Jar talks about giving emergency powers to Palpatine, who is the bald-headed person that is standing with Palpatine and Mas Amedda?
Answer: That would be Sly Moore, an Umbaran who serves as Palpatine's senior administrator. According to Expanded Universe materials, she was one of very few who knew that Palpatine was a Sith Lord and received some Dark Side training to enhance her species' natural ability to influence the wills of other sentients.
Tailkinker 
Answer: He must tap into the Force to perform these acrobatics. Without doing so, he is restricted in movement by his age and limp. He feels it would be squanderous, selfish, and unnecesary to use his abilities with the Force simply to get about.
Phixius