A) Quaffle (the "standard" Quidditch game)
B ) Snitchplay (i.e. taking part in a Seeker tournament)
C) Other broom games (e.g. Creaothceann, Quodpot, Xany, and similar games)
D) Forum activities (creative and puzzles) outside of IRC
D FOR SURE!
A, B, and C will definitely depend on me getting my stuff together and remembering that IRC is a thing that exists and figuring out how to make it work on my computer again