I agree with your analysis of Pittsburgh in most respects. You are right about who supports Biden, Bernie, and Trump.
Biden will get most of the older, retired union guys. Those folks see Biden as FDR, part 2. Biden will also get the current union leadership. But the current rank-and-file...there are more Trump supporters there than the leadership wants to admit.
I think Pittsburgh will go strongly for Biden in November. No big surprise. It’s Pennsylvania I’m not sure of. Remember all those Philadelphia precincts that went 100% for Obama? Not 99.9%, but 100% percent. Even Stalin never tried such a bold maneuver.
Do you live in PA? If so, what part?
I’m on the fringes of Pittsburgh and I see no evidence of a slobbering love affair with Biden here. I think that is largely a myth.
He could well win Allegheny County just on the strength of the reflexive “D” straight party voter.
FWIW, Trump won PA in 2016. Barely, but he won it.
Hillary Rodham 2,926,441 47.46%
President Trump 2,970,733 48.18%
https://en.wikipedia.org/wiki/2016_United_States_presidential_election_in_Pennsylvania