I think it would be great if you could leave personal notes on coaches that noone else could read. Do not know how it would be implemented. I doubt it is hard to do, but maybe it would slow down the site. I think I rather have that then people on lists.

Something like this:

Candeljack (fun to play)
Malitrius (boring player)
Woodstock (this guy is fast)
Flix (unbeatable)
Rijssiej (beware you think you cherry-picked him, but it was the otherway around!)
Zed (something else)

Well the note should show up on the front web page of each coach.