To answer part 1.
PB on its own only enforces 2 minute kicks for the majority of their violations. PBBans enforces a ban on the GUID that triggered the ban, for life across streaming servers.
PB, does not accept Punkbuster screenshots as evidence against hackers, PBBans does as long as the server is streaming at the time. PBBans has its own MD5 detections. For some games we accept in game demos (COD4), PB doesn't.