I don't know if this has been mentioned before, because it got tiresome reading through six pages (so I primarily read this last one), but what I would really like to be added in KOTOR3 is the option to change your name when you turn darkside: as in, "Darth Whoever"
I didn't know if it would happen in KOTOR2, and since I just recently selected the rank of Sith Lord in this, my third game, I see it doesn't happen in this one.
But I really think this would be a great addition to the next one.