-I believe a tracked blitz game is one that counts in your stats and awards, vs. practice, which doesn't (not sure because I don't play blitz, but this is the difference between "ranked" and practice in stroke play)
-the U.S. Golf Association runs the U.S. Open, Women's Open, etc... (as opposed to the PGA). The USGA courses here are courses that have held US Opens. Only Pebble Beach (closest to the hole only) is unavailable, apparently because there was a contract conflict with another gaming company.
-to advance in tiers you have to play ranked stroke play rounds, including tournaments. You have to play a certain minimum number of rounds, which increases as you advance; you also have to lower your "average score" to a certain number, which decreases as you advance. WGT does not release those numbers... and these are NOT the actual ones, only an example to give you an idea
Hack > amateur: 10 rounds, 80 average
amateur > pro: 15 rounds, 76 average
et cetera ... you can get a handle on the actual numbers by looking at other players' tiers/scores
good luck, and have fun. be sure to play ranked rounds and not only CTTH and blitz if you want to advance; and play all the courses, not just the ones that you're most comfortable on.