First round QB's are typically a big crapshoot. There are no guarantees.
I like the idea of drafting a QB PLUS bringing in either Case Keenum or Teddy Bridgewater for a look. Granted, Keenum is going to demand a big contract based on his play this year, potentially like 15-20mm per year for 3 - 4 years.
Teddy Bridgewater might make more sense. In the FA Market, he'd command a lesser commitment, such as a 2 year $8-12mm contract. He showed potential when he was healthy, so see if he can pick it up again when back next year, and put an OL around him. If it doesn't work out, you have Webb and the 1st rounder to evaluate, waiting in the wings. There's nothing wrong with developing a draft QB behind the scenes and not starting him right away.