With how DA2 turned out, I'm weary of this game now.
DA2 is disappointing b/c it appears to be the anti-DAO. People's expectations totally reversed.
Star Wars has a longer history of extremely shitty-to mostly underwhelming games. It's hard to live down to such expectations. That being said--Bioware is responsible for the absolute best of those, and KOTOR was far, far from shitty.
While it wouldn't be fair to expect KOTOR out of this, I can see how failing on that experience would leave people disappointed.
anyway, as far as the dialogue-specific missions go. I can see how dialogue choices-->altered mission details could work by spawning different bosses on the mission, or certainly different outcomes.
Maybe during each characters initial playthrough, the mission choices will indeed limit you until endgame--as your choices change. It could mean that in teaming up with other players, you all have to be on the same track (would have to be limited options to prevent a major clusterfuck of various storylines among all the players).
Then after finishing the game, your same character can return to the quest and mission givers and choose the previous options. I don't know, maybe that's craziness. Sounds like it could work, though.