Legends

It would be cool to get Jan as a rebel to go along with Kyle Katarn and Mon Mothma. Keep Luthen with Saw and move in Jan. Rosh Penn and Jaiden could be a really cool addition to a Jedi team. 

I still want KoTOR 2 characters like the Exile, Atton, Handmaiden, Mira, Bao Dour. They could all be characters in their own right but then when the Exile uses an ability it unlocks a new ability for all of them (When they learn the force). It could be like a bounty contract type of system.

Jaina and Jacen too. Nomi Sunrider can't be done for copyright reasons with the author using her name in non-Star Wars media (same reason she was replaced by Bastilla during KOTOR 1 development)

Definitely more Legends-exclusive characters like Desann, Jerec, Tavion Axmis, C-3PX, Trioculus, Darth Caedus, Admiral Screed, Marka Ragnos, Freedon Nadd, and the ones which you've mentioned.