if people hate alien speak..... there's a REALLY simple solution to your problems. don't play that species!! omg i know, it's so cutting edge! but trust me, it works! and when you're spacebarring through your flashpoints, you still won't have to hear it! omg, right?
Honesty my opinion is that if you create a character who generally doesn't speak basic that somewhere in the game there's a preference toggle to set whether or not your character speaks basic or native. There could also be a 2nd toggle for "Make friendly players always speak basic in conversations" That way if I group with Tux playing a Wookie and I have native on but he has the make friendlies speak basic then on my computer the auto for a Wookie plays but on his the existing class voice over content is played.