Hasselbeck is an awesome matchup; I am starting him over my regular starter (Matt Ryan) in one of my leagues as well.
However, I'm not totally sold on Schaub's health being a problem this week. He's been a full participant in their last 2 practices and seems good to go. I would start him over Palmer, though it's admittedly somewhat of a crapshoot.
Realistically, all 3 QBs have favorable matchups this week, so you're in decent shape either way. But my gut tells me Schaub over Palmer, Hasselbeck over Schaub.
Thanks for the help with mine!