My piloting experience is limited to a Cessna 152, but the mainwheel brakes on an aircraft are operated separately, allowing the pilot to use differing pressure on each side to steer the aircraft down the runway - below a certain speed the rudder becomes useless, anyway. But I'd have to agree that having the nosewheel locked at 90 degrees would have to be easier to control than any other angle. Other than 0, of course...

__________________
"Properly read, the Bible is the most potent force for atheism ever conceived." - Isaac Asimov