Steam – How long does a Booster Trooper guest pass last

It doesn't cost nothing - it costs time and convenience to create different accounts and log in to them all separately when you want to change which account you are using.

I searched through the User Agreement. I think you're correct in that this is not specifically prohibited. Similarly, using multiple accounts to purchase multiple copies of the same game and multibox is not specifically prohibited (to my knowledge).

If you are the kind of person that would actually want to play different games at the same time, it does make sense. However, I cannot think of a legitimate reason to actually want to play multiple different Steam games at once. I have a hard enough time being good at any 1 game I'm playing.

Should you be doing this? In my opinion, no. I use the community-oriented features of Steam all the time and the Cons you list would affect me greatly. Having multiple accounts would be a tremendous inconvenience for me, and I don't care about any of the Pros you list.

Exceptions: There may be some games where it would make sense to have a separate account for just that game. I hear you do a lot of sitting around in games like Eve Online; perhaps you would want to play Bejeweled while you wait for something to happen?

I discovered Steam's "Repair tool" in the installer. I'm not sure if it matters, but during my earlier troubleshooting, I deleted everything in my Steam folder except for steamapps, userdata, and "Steam".

The Repair tool ran for quite a while (it seemed to be stuck at the end) and then when it was finished, the update went off without a hitch. It took a few minutes to remember that I'd already downloaded most of my games, but it seems to be in its original working order!

I'm not sure why they don't mention this at all in their troubleshooting article...