I didn't know MM2 had a track designer... I've only played the Mega-Drive version, and this version has no track designer...
I haven't tried any other multiplayer modes, only the "Share Controller". As I don't have a multi-tap, we just can't get over the urge of playing with 4 players. Playing with just 2 now would feel weird
But if I had one, yes, I guess we wouldn't go for 8 players mode (Well.. maybe for the curiosity sake), we would be fine with 5 players.
The shortcuts aren't exactly "random". There's a certain logic behind them, just like in the original Micro Machines. But MM V3 seems to have bigger shortcuts, which may give you a bigger advantage, but the bigger it's, the harder it's to go through it (As ther will be more objects in the course)
The graphics aren't bad in my opinion. Like in the other MMs, they are functional. They are much better (even in 3D) than the previous versions, with a lot more of detail in the tracks.
Micro Machines got a PS2 release, but I haven't see it yet.