Matt Schaub is a franchise type QB. Our OL is only going to get better with Kubiak/Gibbs making the picks and coaching them up- my only hope is that it's sooner than later.
Sage isn't going to be a long term starter in the league but is a VERY good back up as evidenced by this last season. If you need him to come in during the game or even to make a few starts- I wouldn't chalk those games up as a loss at all.
I don't really see a place on the team for a QB being drafted or as an udfa this year. The biggest reason I would be for it, would be for Kubiak/Shanahan to groom and then trade to another team. Like when we drafted Drew Stanton in the 6th round- then traded him a year later to Dallas for a future 3rd round pick. That's what I thought we had a chance at with Zabransky last year but didn't look like it was in the cards. I think Kubiak is more interested (as he should be) in getting the players He wants, maximizing the 53-man roster, and getting everything he can out of everybody to have a successful season and future seasons.
I think he's found his QB's in Schaub and Rosenfels and I don't see them going anywhere for a while.