Yes the K3 PC could be going from system to system to gather forces to defend the Republic and to gain the senators trust.
We could at last see the Jedi temple on Coruscant (enough with Dantooine already).
I think the job of that should be given to Revan.
Backgrounf to Revan:
He went to face the true Sith but after some time he got captured/trapped and then the exile comes to the rescue. We could start the game with the exile and go to rescue Revan
They barely escape with their lives, but they have managed to steal some plans of the true Sith regarding their attack.
Revan must be the one who'll face the Sith since he knows more about their weaknesses than anyone else.