In game, I see a lot of AFK (away from keyboard) players. Does being AFK allow you to get items from the item drop system?
Yes they can get item drops. However, there is a limit to the number of items that you can get in a given period, so idling for items has limited benefit. Valve tweaks the system every so often to try and discourage idling for items.
From the TF2 Wiki:
Furthermore, I believe Valve is capable of tracking people who have accounts solely for idling, and mark them with lower drop rates. That much is speculation, based on observation of a relatively small sample size, although there is precedent.
Server operators can install plugins that kick idle players off after a period of time, and there are even servers that exist for the sole purpose of idling and trading items, so you should shop around in the server browser until you find one that is routinely policed for AFK players, if that is of concern to you.
Yes. All that's required really is to be in game and connected to the relevant Steam servers.
You can very simply click on "Steam Workshop", pick "Start test map", join a team and leave for the night. When you're back, suicide yourself and you'll get your drops. You can even get drops without starting the game proper on Windows, as the TF2 wiki reports, by using the