Regarding rosters, that looks great to me even if you decide to go with 16 teams 12 is a good number it probably wouldn't hurt to take out one bench but I'm fine with it at 12.
There are 4 team managers I'm not familiar with. Two of them, I'm pretty sure, are Sonics fans. This is because their team names are "FU Clay" and "Skyway Sonics". The other two, I have no idea. They are "TeamFAAACK!" and "Still Strong". There is a slight chance they're holdover OKC fans who didn't quit the league when I asked them to.
I think with a team name "FU Clay" there is a slight chance that is run by a Sonics fan.
The other two you mentioned joined when that post was made on the OKC board, I am almost positive they are outsiders. If you decide to boot 2 teams, boot them.