All right, I understand. I vote no on your idea though.
Mainly because combat like KOTORs could not keep me interested for 180 hours. Especially if we are talking about three game series, that's 2-4 years in between each one. I would expect the combat at the very least to evolve, that would mean new way of learning force powers, feats, skills.
Having your character start at level 1 after every game would be ideal for this situation.