Re: How close should a comic book movie be to its source material?
Depends on what it is you're changing about it.
For example, a character from the comic has three aspects that can be altered, but the three are not equal in terms of importance.
Appearance: Appearances have been altered in almost every comic book ever adapted to big screen, some minor, some major. These are fine as long as you don't go over the top with them and keep them at a strictly cosmetic level, though some might be more ridiculous than others.
Backstory: Alterations such as location and names of people who were key elements in the character's growth can vary depending on how similar they are to the comics. For example, If a character's origin was in the north pole and it was changed to Antarctica for a film, that's minor. However, if the character is an earthling and was changed to outer space, that's major and cause for concern.
Personality/demeanor: By FAR the most important aspect of any character, and should be altered very marginally, otherwise you may as well just make an entirely new character.