Otaku-san said:
@ilmaestro: also it's not just a name to be put at the end of the credits but it's whats behind the name that counts. So when there's a new film that has Nicolas Cage as the star, it's not just a name
I'll be honest, I haven't got a clue what you mean here. Or, at least, what you're trying to say in the context of name pronunciation.
On a possibly tangential note, would it make any sense for Japanese people to pronounce his surname "ka-ge"? No, they try to get as close as possible to the "proper" pronunciation, allowing for the limitations of their own syllables. In general, I don't think those limitations are there in English, with a couple of exceptions.