Your answers appear to be all answered, but just to add to the point about the risk of "frying" your PS2 by leaving your PS2 on over night letting B-spec do a 24 hour race for you.
I've done several 24 hour races in A-spec, pausing the game between 1-2 hour stints, thus sometimes it meant having my PS2 running non-stop for a couple weeks at a time. I have also run far more 24 endurance races in B-spec, especially the Nurb when I was trying to get all the different colored FGT cars.
In addition, my PS2, while not the original release model, is also pretty old. I think I got it in the summer of 2001, so about 9 months after it was released in the US. There is no build date, only a code: 1B and model number: SCPH-30001
So besides having an old PS2, and besides leaving it running for weeks at a time on the rug floor of my home office... hardly a great place for air circulation, and I've only cleaned it once about a year ago when it didn't read my WRC game disc... even though it was very dusty it turned out the problem was the disc which I replaced and works just fine. I have not once had a single problem with my PS2, so I seriously doubt you would ever risk hurting your PS2 by keeping it running for over a week at a time. 👍