I won't argue much here, because all are entitled to their own opinion. That said, your counterpoints all fall into the correlation vs. causation differentiation. The early scores and the 3 v 3 are a) largely due to superhuman players named Makar and Mackinnon and b) lacking context. A good chunk of both of those were against teams which did not make the playoffs. So did Bednar CAUSE those statistics? Or did he happen to be around? Similarly, giving Bednar credit for 'developing' Makar is a stretch, and Mikko and Byram are close to that level ( and Mikko was developed in a Loveland year not Bednar.) Sure, the Avs are back up to top-10 in PP goals, but the Oilers are 1st and the difference between the two is clear as day ( and it is not personnel. The Oilers constantly move bodies on the PP, not just the puck. That is a coaching issue.)
My point, in general, is that the Avs have a handful of all-world players who cause both their success and most of the metrics you mention. Bednar is along for the ride.
He's not a terrible coach and by all accounts, a really good guy. But we gets waaaaaaaaayyyyyyy more credit in here than he deserves.