They're working on a patch for those stuttering problems. There is a preliminary patch they released which fixed some of it. It's something to do with the way Source handles texture swapping.
That's cool, with 1 gb of RAM you'll be more than set to play the game. The Source engine is VERY scalable so you should be able to play with good quality and speed.
From what I've been reading everywhere, it seems Blizzard hit the nail on the head with this game. Hell, this game won best PC game of the year at Gamespot.
Here's an unofficial Suprnova Closure FAQ: - Website Links to Torrent Sites - Damn, that thing has links to torrent sites. But if you want to read that go to Slashdot.
Yeah, Steam implemented a backup feature sometime last month. And once you buy it from Steam, you can download it as many times as you want but you can only play it from that account.
No, I don't think dumpsters are that advanced yet. And I don't think any garbage workers get off the truck to see if anyone is inside since they have those massive hooks to lift it up.