the pics are also under your 'gamertag'. here's mine:
Steam Community :: daze23 :: Screenshots
it's up to dev's to stop cheaters on all platforms. it's more prevalent on PC because of the open nature of the platform. Valve does have VAC, and many 3rd party games use it
the cloud storage is effectively 'unlimited' just like consoles, in that you'll never use it all
I really don't find these distinctions compelling enough to call Steam's service "barebones" compared to consoles. it's pretty much the same shyt, and some of this stuff was on Steam first. do consoles even host forums for every game?
last I checked, you never even set up a Steam profile. so I'm not sure how much experience you have with this