He or Charlie dent would be the best gets for the senate race. I would wonder if Rick Santorum would be interested in a rematch as he has had his reputation somewhat recover since 2006 and the state has trended to the right
A majority of Pennsylvanians support gay marriage now. He'd have to say "I oppose it as a traditionalist Catholic, but we need to move on from this ruling" in order to even have a chance at a political miracle, let alone an actual win.
Yes, which is why most republicans running in 2016 including Trump and Pence said that they would not change the ruling. In addition I think most people now view him as a social conservative who ran for president rather than as the hardcore anti-gay senator