I think that maybe Canderous should finally die, but it should be "going out in glory" kind of moment. He should probably end up becoming a Mandalorian hero that the rest of the clans hold in honor, or something. You know, have a big battle, maybe they are your allies and they are helping you fight the Sith, and then they get forced back and Mandalore goes running out and tries to take them all on single-handedly. He dies, of course, and they lose, but he still defends and saves his clan, if only for a little bit. Just make him have a glorious exit at least.
I think that maybe Carth should die in a battle too, his ship destroyed as he is defending Telos- very emotional, of course, but he should have a "good" end too.
But, there should be some major character that dies, perhaps another one of the characters from the earlier ones, or maybe a new prominent character (or even maybe a party member) could have a dramatic and emotional death. Or maybe even Revan and the Exile- although that would probably only happen if they were the opposite side or something.