Live action movie?!?!?!?!?! NOOOOOOOOOOOO!!!!! REALLY BAD IDEA!
That would definetly not do the KH series any justice.
Instead of live action, why not animated? like, the animation you find at the end of KH2, where it looks life-like. Although I don't think it'd be so good, it'd look cool. and there'd be a lot of stuff to iron out. like, Sora fighting, and there wouldn't be any items, such as potions and ethers or the clothes items that boost def/AP. And it'd be really long and it'd be really simplified and I just don't think it'd work out well. but if it were to happen, I would rather go and see an animated one, because you just can't look like a video game character in real life, and it would just suck that way.