Um. No.
That's a terrible plan.
I agree that the price is very steep, your top 2 picks. However, Here is my logic:
Schaub has proved he can play and be a very productive NFL QB, unlike Leinart, Young, or Cutler. He's going to be a very good starter. There was an article I read (possibly from a link in a post here) that a NFL executive or good writer said he'd trade for a guy like Schaub who's proven something at the NFl level rather than take a risk and draft a QB. Mike Holmgrenn traded for Matt Hasselbeck with a high pick (was it a first?) while he was still sitting on Green Bay's bench and having seen far less action than Schaub has so far. Schaub has also been playing in a WCO in Atlanta and played in a hybrid WC system at Virginia. Mike Vick hasn't reached his potential yet (and may never do so) and Schaub might be the best QB in Atlanta right now.
Walker's trade hasn't happened yet so we don't know what he will go for. It's possible with the bidders out there he could merit a first round pick in return (think late first round to a team like #31 Seahawks. That would be a scary WR core, Walker, Jackson, and Burleson as a #3 WR) although I think it might be unlikely. A second would probably do it. The injury is scary but there aren't many WR's you can obtain like Walker so I think a two, although risky, would be worth it.
If you could get either of these guys for less than what I've said, Scahub for a second or Walker for a third, then it would abviously be more palatable. I didn't say you couldn't go for that. I was merely throwing out the 1 and 2 picks as ones that would get the deal done most likely. And I think I'd be OK with it if I were a GM.
Also, Minnesota has gobs of salary cap money so they could get these deals done and lock Schaub and Walker locked up long term. I'd even go so far as to
FRONTLOAD the contracts so that you have cap flexibility in subsequent years, much like when the Vikings signed Antoine Winfield in free agency and rather than giving him a big signing bonus (which spreads out over several years) they gave him a lump sum
roster bonus due the first year of the contract which counted against the current year's cap. You could build a helluva team like that.
Getting two cornerstone positions, QB and WR (in addition to LT, DE, and CB), locked down long term would be a major accomplishment.