Question: By the end of the movie, the whole plan of the bad guys is to let Nyah in the middle of a populated city so that she infects a lot of people. But she just walks away to a cliff to kill herself. Even if Ethan failed to save her and kill Ambrose, the plan was not going to work. Or am I missing something? It sounds like a very poor plan to me if she could simply frustrate it by walking away.
Question: How did Ethan Hunt know he was going to switch places with Hugh at the end of the film requiring him to take two masks with him to swap different faces?
Question: Why didn't Ethan just give Nyah one of his guns after she infected herself? She could have easily killed Ambrose and others with a surprise attack since they were more interested in keeping her alive and she wanted Ethan to kill her anyway. She had better odds of surviving that way than the impossible plot that followed. She could have killed everyone but Ambrose and he may have let it happen in order to still have a chance at selling the virus.
Question: When Ambrose noticed the envelope was in the wrong pocket, and was thus tipped off that Nyah was a spy, how did he jump to the conclusion that Ethan was her contact? Did he play a mere hunch when he impersonated Ethan in front of her?
Answer: Ethan was the most probable candidate. Remember that Ambrose and Ethan had specifically worked together a few times with IMF in the past, as stated in the film, with them body doubling each other. Once Ambrose had his suspicious raised by the envelope, he decided to test Nyah. So showing up to her with Ethan's face would indicate if she recognized Ethan, or thought she was being approached by a total stranger at night.
Answer: Ambrose has stolen Chimera, a virus developed by Dr. Nekhorvich. Dr. Nekhorvich was an associate of Hunt, and trusted him. This is why Ambrose had to pose as Hunt to extract him at the beginning. Given that Ambrose was posing as hunt on the mission he went rogue, it is logical that Hunt would be the one sent to take him down.
Question: What is supposed to be in those biohazard tanks that makes them explode so violently when shot. Considering what is stored inside them that seems like a stupid way of storing dangerous things.
Answer: The contents are either some sort of flammable material (i.e. magnesium hydride) or some sort of material that would ignite a flammable material upon contact (i.e. hydrogen peroxide) that would easily explode violently when ignited (i.e. with a bullet.) The containers are actually decent as they can withstand falls, but they are definitely not bulletproof. After all, one doesn't expect someone to come into a laboratory and shoot chemical storage containers.
Question: What style of black leather jacket does Ethan Hunt wear just before the chase scene near the end of the movie, I've been looking for ages trying to find something similar?
Answer: The costume designer was Lizzy Gardiner, who can be contacted through Sandra Marsh Management (smarshmgmt@earthlink.net). The IMDb is the best place for questions like this.
Question: Throughout the film, Hugh Stamp's accent keeps changing, where exactly is he supposed to be from?
Answer: South Africa, although the actor is Australian.
Question: Why didn't IMF just raid Ambrose's house when they realised he only had a cure and no virus?
Answer: As Ambrose says, Ethan Hunt "favours misdirection over confrontation" - Ambrose's house is heavily guarded and fortified, and an armed raid could result in the deaths of IMF personnel including Ethan and his team, or other innocent parties such as Nyah. Better to break into Biocyte covertly and destroy the virus, with a much lower risk of casualties.
Question: How did Ethan know the location of the meeting between McCloy and Ambrose on that island?
Answer: Luther brings up the schematics of the Bare Island facility when they are looking up the plans for Biocyte's headquarters. Also remember that Ethan and his team abducted then released McCloy earlier on to find out about the cure, so they could have copied and analysed the contents of his briefcase such as his diary and phone to pinpoint the meeting with Ambrose.
Answer: Ethan did not want her to kill herself. Giving her a gun would allow her to do so.