Dalton is Jay trying to save what's left of his job or reputation. I don't think Dalton will sign anywhere on a 1yr deal and I'm betting that's all Jay's getting as an injury do-over and he knows it. So the only way Dalton comes to DC is if the front office really, really likes the guy regardless of Gruden, or if they somehow are open to Gruden staying and are willing to throw money behind it (doubt it).
That coupled with the obvious tank flag of starting McCoy week 1 tells me they need to draft a QB this year even if they're hoping to land another next year.
Promoting your passing coach to OC implies the QB position and probably the offense will be held together with duct tape and spit. "You know what we have, make it work somehow".
Also, on Flacco, he has a lot of money already and he's close enough to DC to know how things work at Skins HQ. I doubt he wants to play for Snyder and sure as hell won't want a 1yr deal (or a backup/mentor role).