Although a good suggestion, it wouldn't work. See, in this MMO, conversations are VERY common in group activities. Despite whatever "I" select for a race, I'll be forced to listen to Greed'yo speak gibberish. I'm with Bioware on this one.
Of course, however, you wouldn't really experience significantly more of than you do now unless you ended up doing Flashpoints exclusively with Wookiee's and always lose the conversation /roll.