Question: How is that Poison Ivy, Mr. Freeze, The Riddler, and Cat Woman can suddenly have perfect vision after going insane as well as their accidents?
Answer: Most of these, if not all of them, had something supernatural happen to them. This supernatural event enhanced their abilities, their bodies. This includes their eyesight.
Question: How was Pamela Isley aka Poison Ivy able to fight Batgirl with martial arts-like skills towards the end of the movie? Pamela was a doctor and I highly doubt given her obsession with her research she had the time to take martial arts lessons in her spare time, if she had any during her stay in South America. Even after she transformed into Poison Ivy, her transformation could not have given her martial arts skills since her powers are based on plant abilities.
Answer: There's no way of knowing whether or not she "had the time" to study martial arts. Regardless of her studies, she could have made time to pursue this as an extra-curricular activity. Universities can have classes, clubs, competitions, and student groups for martial arts on campus that anyone can participate in. She may also have been studying it since childhood. She was also a botanist, so even with a rigorous academic schedule, she would likely have more free time than a medical student.
Answer: That and they had to have the women fight in here. I mean they couldn't have the guys hit her now could they? So it was necessary for her to fight competently at least.
Question: How does Ivy get Nora's snowflake necklace without getting her costume soaked in the cyro fluid or whatever it is?
Answer: Maybe she drained the cryo-tube first? Maybe she did get wet but had dried off by the time we see her again? Maybe Bane did it for her? Pick whatever answer works best for you. It's a really small, insignificant detail in the film with plenty of potential answers.
Answer: She most likely used her mind control potion on someone and had them do it for her.
Question: How does Mr Freeze get placed in Poison Ivy's cell, and why does her floral throne turn on her?
Answer: As to the first part of your question, Mr. Freeze was temporarily placed in Poison Ivy's cell while his own cell was being remade into a lab for him to continue his research.
Thanks, in the book version of the movie he bribed the guards with diamonds used to power his suit. That and everyone forgets she's a victim like him, not asking to be turned into a monster, so it just seems unfair.
Question: Why didn't Val Kilmer play Batman for this movie? Was he not offered the part? Did he not want it? What happened?
Answer: When Barbara told Holligran Alfred, she wanted to help, he said, "I prepared for this." He gave her a suit, which meant he equipped it with the latest tech. After years of serving Batman, it's logical to assume he put a GPS tracker into his batsuit.