I think you should start doing all official tournaments with 7 rounds and not with 5 because it’s too short. Also change the tiebreak system the first tiebreak has to be the result of their individual game.
You are right on the money when you say the first tie-break should be head-to-head. I would also say if the head-to-head game is drawn, the player with the black pieces should take the tie-break.