Obviously too many players. Training camp/injuries will determine who stays up (especially on D between Wotherspoon, Kulak, Andersson, and even Nakladal/Engellend. Hathaway, Jooris, Bouma, Shinkaruk and Ferland will be fighting for spots, and I think if Treliving can get Grant back, he'll be a fixture on the team this year.
If we don't get Dubois, we'll get Tkachuk (I'm pretty sure Oilers will take their top dman at 4th overall.)
Get Reimer Calgary!!! He'll be better than everyone/anyone expects...
Trade Wideman for a 2017 draft pick and a bad contract that can be put on LTIR (or a lesser bad contract on forward that can be buried in the minors to reduce cap hit).

Even with goalie market flooded I think you'd be pretty lucky to get Reimer for 3.6. Probably add around a million to that cap hit (Niemi went for $4.5 per last year.)

Re: the Pronger thing - it seems to be a popular option on here, evidently based on the notion Arizona would rather pay a guy to actually play. But here's the key fact people miss - Pronger's ACTUAL SALARY for his final year is just $575K. It's why they traded for that deal, so they could get to the floor without actually paying what the cap hit implied. (It's also why his contract is even still in effect, since it was one of the now-banned cap cheat deals). Wideman, on the other hand, has an actual salary of $6M in 2017. So Arizona would be doing Calgary a favour in that deal, not the other way around. I wouldn't call it impossible but improbable; Flames likely would have to throw something in.

I didn't know Skrollings, thanks for the info. In that case it is very improbable, or the Flames would have to sweeten the offer as you said.