For the record, I will be running an activity check at the end of Chapter One. I will do so at the end of every chapter from then on, unless it's obvious we don't need one. Players that do not meet AC will be warned and docked XP for missing AC.
Further activity things:
Players not participating in combat and other risk-taking situations (such as not responding to Save calls, etc) will be docked experience and treasure shares as if they had missed an in-person session. The XP docking will be arbitrary, but treasure allotment is in the hands of the players.
There is a difference between "not participating" and "not fighting" in a combat. A character that ducks behind a pillar and runs like hell at the sight of some angry goblins is participating, but not fighting. They may or may not be given experience depending on the situation. A player not responding for the entirety of the combat is "not participating".
Any questions and/or suggestions may be posted below.