F1ach: Do I understand you correctly? If you buy a downloadable game from PSN, you cannot play it if you stop being a PSN member?
No. First, there's no way to "stop" being a PSN member because it does not require any subscription or anything, unless you get your account banned, which is unlikely. Second, even if something happened to your PSN account, i think the games that you already had downloaded will not be lost, because PSN games can be played offline, and don't even require signing intp the account you originally bought them on. This is why some people "share" PSN games.
What he was talking about is PS+, which is a subscription model that gives users free games every month (ranging from minis, PSX and even full AAA PS3 titles, such as inFamous 2, LBP2 and Warhammer Space Marine), discounts on games, cloud saves, access to game betas and other features. In THIS case the games that you get for free are only available as long as you keep your subscription up. If you let it expire, the free games will be lost. But of course you don't lose the games that you bough on PS+ discounts.
EC-: 1. The backwards compatibility for PS2 was split into hardware emulation of the original 20GB/60GB models, and software emulation for the second batch of 80GB models. The second batch with software emulation, judging by my research through many Playstation forums, has a lower hardware failure rate than the initial models.
2. This particular PS3 has literally been boxed for over two years, and never turned on. I realize that this doesn't equate automatically to good hardware, but I believe the lack of stress on the disc drive will help when using the Playstation.
I have the same PS3 model as yours, a 80GB with PS2 compability through software emulation. Keep in mind that the software emulation is very hit-and-miss. Some games work perfectly full speed like they would on a PS2, but some don't. Anyway, there's a link on Sony's site that you can just type the name of the game and you'll get information about how well it runs on softwarte emulation (if there are any issues). Ratchet and Clank games are the most famous for not running well on sotfware emulation consoles. If you want to play these games, wait for the HD collection. I prefer to run my PS2 games on my PS2.