Hey Shadow,
I'll be the annoying voice here

I'm guessing this thread is more about "what if", but here are a few things I wanted to mention!
You may know this already, but making video games is all about compromises, especially on an aging console like the PS2
Indeed, the things you described in the wish list would definitely make for a better game, but again, adding most of them would mean removing something somewhere else.
The general consensus amongst PS2 developers is that Gran Turismo is quite kick ass and quite pushing the hardware as it is.
I heard Polyphony (Sony-owned developer) already have better running physics and such using multiple PS2s together, but unfortunately that isn't a setup most consumer have at home.
I'm guessing they'll do miracles on the PS3, whenever that's coming out
Anyway, didn't mean for this to sound like a rant, but rather I wanted to let people know that more often than not, when something's missing from a game it's due to compromises that had to be made, as opposed to developers just being lazy

Geoff