I wouldn't call them "canon", but they seem to be a representation of possible PC characters. The game's boxart has similar ones for a Jedi Knight, Bounty Hunter, Trooper.
No. Those are known NPCs from the game's backstory.
The jedi is the guy that gets killed by Malgus during the Sacking of Coruscant-trailer. Shae Vizla, the Bounty Hunter chick, is also present.
The trooper is in the Alderaan trailer, together with Satele.