This time, I don't want any of the characters returning as your party members, ESPECIALLY HK-47 & T3-M4 - I mean, we've had them twice already, which was fair enough (I'm not complaining at all about them appearing a second time) but please, no third time. They just wouldn't be interesting anymore - what else or new can be done with them? Even if they were done so that they didn't become repetitive or parodies of themselves, I'd still prefer absolutely raw material through completely original characters.
However, I would very much (for the sake of continuity) like to see many of the previous party members in cameo roles instead. As many as possible, without having to alter the storyline too much to fit them in (as long as it makes sense, why they are where they are, and doing what they are doing, basically).
But either way - deep consideration needs to be placed upon what is considered "canon", and also if - like in TSL - you can choose the previous games' outcomes. 'Cos like, if you choose that Revan went DS again during the Jedi Civil War, then Jolee and Juhani are dead in your game, so therefore (unless as ghosts) they cannot be present, etc.
"Someone's gotta get tough,
or someone else is gonna cry"