Mine always have preload, I'm too lazy to adjust the bars twice a week. Considering I race the car nearly every weekend and drive it around M-F I just leave it alone and deal with a little stiffer of a ride.

As for wearing out the monos I'm not sure, and I haven't given it too much thought. Theoretically every time the spring compresses and rebounds it wears out a little bit. As for if the bars compound that action I would guess no, but I've been wrong before.

-Dustin