>>1 Mainly because all anime companies find it cheaper to record local voice actors and their main target viewing audience are Japanese people first and all other second.
Take for example the anime "chrome regain shell" it had Japanese voice actors doing English in the small t.v series with in the anime.
Yes they could do what you are asking but it would have to be a very damn popular manga first to then be made into the anime you want, and then we would have to wait for the dubs.
You likely will have notice that they do seems to use a lot of odd bits and pieces of other languages in anime I,e "Blue Exorcist" Mephisto Pheles counts in German, ect