Wasn't trying to make you sound silly. Just expressing my outlook on the situation.
Also, the emotion engine isn't compatible with ALL PS2 games. Its simply an emulator, and anyone who has ever used an emulator before can tell you they are far from perfect. You will run into glitches or on occassion games just straight up don't work right with it. That was part of why I said I'd rather just have an old PS2 sitting next to my PS3 (which I do).
As for the USB ports... I've never had to charge both of my controllers at the same time. They charge fast and the charge lasts quite a long time. Also to be noted, getting an old model you are getting the old crappy controllers, not the new dual shock hotness. I think I charged my controllers about a month ago and they still have over half battery left right now (just checked).
Another thought... the first wave of PS3's had huge problems. Some overheated and fried themselves 15 mins after being taken out of the box. Could this fear be why the guy never opened his and decided to sell it? Not to scare you, just trying to make you aware. Online people can seem nice and friendly, but you never know what you are truely buying or who you are buying it from until it is in your hands. Remember after all, they are just trying to make a buck.