OMG, are you me? And I hated Elway. We used to say mean things about his teeth and laughed every time he choked in the Super Bowl. I don't feel that way about him now, necessarily, but I still wish he had retired without a Super Bowl ring. Sports can bring out the petty in me.
Hard to say - so many Mormons are football illiterate. I saw a lot of Broncos fans but a lot of people like a certain team either because they liked a certain player OR because they served a mission there. One of my friends was a big Oakland Raiders fan because he served a mission in the Bay Area, even though he lives in Utah now. He has very good taste in football teams, IMO :) But we are also big Saints fans because my DH served a mission in Louisiana. So where, in other states you are fans of the local team, I saw a lot of Mormons rooting for other teams than Denver for reasons like those.
If I recall correctly one of the TV stations took an unscientific poll a few years ago. If I remember right, for those who answered it was somewhere around 1/3 Denver, 1/3 SF, and 1/3 other teams. Maybe a little more toward Denver and SF than other teams, something like 37.5%, 37.5%, 25%.
When I occasionally see bumper stickers or people wearing hats/shirts/jerseys, I would say I see mostly Denver, followed by SF.
Yes, I think a lot of the SF fans are holdover from the Steve Young era. To read the Deserted News and the other local paper you wouldn't even know pro football existed.
I really think Utah needs to get its own team going. Like it or not, BYU has very good players that come out of it, and the U has many that go into the NFL as well. The in-state talent isn't the greatest, but it's pretty good and could draw a lot of attention in an increasingly non-mormon state on Sundays.
Besides, I think a lot of people in Utah would start to support the FB team even if it "sucked" because we don't have one, and don't really have too many professional and nationally recognized teams. (I can count them on one hand: RSL and Jazz)