I agree about the vehicle problem in UO. Played the Kharkov map and it was all armoured vehicles. If you played as an infantryman you lasted mere moments. That is once you actually made it all the way over from the spawn point to where the actual fighting was taking place.
Aim bots? I often wondered at how some of the phenomenal accuracy was coming about, when the kill cam showed how I'd just been picked off with a single shot whilst nothing more than a mere speck on the screen.