They were give conferences a number of bids per weight class based on the number of wrestlers in that conference would would qualify were all available spots at large. In this way a lower ranked wrestler can "steal" a spot at NCAAs by having a very good tournament. After that there are a handful of at larges, so if a guy that would have been a decent seed gets upset there is a good chance they get in anyway.

The individual national champion is simple. It is the person who goes through the winners bracket unbeaten. The team is more complicated and there are a lot of factors. The team gets points for advancement, bonus points for majors, TFs, and falls, and placement points for AAs. The vast majority of your points comes from AAs. Most national champions score 25-30 points. It is hard to score more than 4-5 points if you don't AA. To get a team trophy you need to be top 4. Why it isn't top 3 I'm not sure, but it is what it is. To be top 4 you need at least 80 points and potentially more like 100.