Getting a third ps3

[Eidolon]

So i have two already, and a freind was going to stick his ps3 in his cellar as he's not longer using it. Considering thathis Laserdisc player that he'd put down there had gone rusty and packed up as a result, I suggested he pass the ps3 to me instead, as I can use it in another room as a bd/dvd/youtube machine, with a bit of gaming.

However, looking online, it looks as if that might be a bit tricky. There;s a lot of conflicting info out there on account of Sony chaging things at different points in time, and I'm a little lost on if I can log onto this third machine using my account?

I'd rather not have to keep deactivating and reactivating consoles, and I'm not sure if it auto-deletes downloaded games or something in these situations?
Sony don't seem to have any help email address for me to ask them.

So what is the situation for me here? I'm really not sure if I can use this for playing some of my games on as well, or if I will have to set up a different account?