This makes it no fun for me. Especially when I come in from work and within 24 hours I have 40 pages to mod over. Who has time for that? With a full time job (at the time) and other hobbies, I can't afford more than a couple of hours of Mafia a day, and nor should I. It's a hobby, I blame MS partially for causing me to get lesser grades in uni because I did all-nighters. (time check - 4.13am at the moment) It's not good or healthy. People usually spend a few hours a week on a hobby, not approaching a day a week! Remember that was in 08/09 and I was in at most 4/5 games which were posting significantly less frequently. (albeit with significantly more analysis and content per post - rightly or wrongly)
What are the things that a player should be doing for you to say that a player is playing the game? (to what extend should they read the thread, what kind of quality of posting do you expect, what quantity of posting do you expect, how aware should they be about what's going on, how much do you expect them to think about the game, etcetera)
My opinion changed on this as the meta changed. I used to think every post should be read. But having been through those multiple long page arguments and the occasional page of one liners from one poster - skipping those parts are fine. I expect insightful posting, not masses of content but enough to know they are interacting meaningfully with other players.
What are the things that a player should be doing for you to say that a player is playing the game well?
Posting insightful content. (a one liner can be insightful) Responding appropriately to questions and posting enough to avoid being prodded.
How much time would you expect a player to spend on each of the points above?
Depends on a number of factors - enough time to read the thread, comment, start a new topic if the ones being discussed don't interest... if the other players have been active then it may take longer, but as I am adamant it's a hobby no longer than a couple of hours at most, and furthermore less time if you have spent more time on it recently.
How would you expect that time to be distributed throughout a week?
Again depends on the activity of players, the type of game, etc. A few hours a week seems reasonable.
To what extend do the answers to these questions differ between individual games?
Answered above
Is there a difference between what you would like the site to require, versus what games on this site actually require?
Absolutely, otherwise I'd still be playing. Games currently require more of a time commitment than I can give, and unless it's changed recently more of a commitment than most should be able to give. Thats due partially I think to stricter deadlines and posting rules and partially to do with the really active players being allowed to dictate the pace of the thread.