Some things that would fix the mistakes it's older brothers made:
1 - As said before, the same planets are boring. And I will not buy the game if there is no Coruscant (this could be a jk)
2 - No main villians following you around until they reveal themselves in a final boss battle followed by their apprentices (I'm looking at you, Kreia)
3 - Please (oh plz!) don't have you're party members knocked out at a crucial moment, leaving you to escape a Sith base while dragging your unconscious teammates to safety and/or fight a super tough Mark III droid with dozens of gadgets when you're only at level 2
4 - No old man, no humor. Keep it real
5 - Don't stick us on a planet at the beginning of the game that takes 2 weeks to beat to get the ship and visit other planets (Example: Taris, Peragus Mining Facility
)
That is all