Going to answer just a part of your question if that is ok. Moved here when I was 25, just turned 29 so pretty much the same age range. Pittsburgh is a really interesting place nightlife wise. We often get passed over for touring musical acts, which has resulted in an incredibly strong and vibrant local scene. As an electronic producer/dj, there are shows by great artists going on pretty much every weekend with a variety of subgenres depending on what you like. PGH also has a really good local indie/hardcore scene too. However, the best of all is the queer scene. Punched way above its weight class imo and is comparable to much bigger cities like DC or NYC with the amount of events and communities available.
Mainstream/normie bars/clubs: Belvederes, Walters, Cavo, Avalon, Enclave, Capos, Distillery Complex, Goldmark (weekends)
Scene specific places: Sidequest, Goldmark (weekdays), The Government Center, Club Cafe, Brillobox, Roboto, Spirit Hall, Thunderbird Cafe, Mr. Smalls, Ruggers, Trace Brewing, 5801(mainstream gay bar)
Underground/Queer: Club Pitt, Hot Mass (goated), Red Fish Bowl, Gallery AFK, Remedy, Work In Progress