I didn't have time to read everyone's posts here so sorry if this stuff is repeated stuff.

I change tires...to old tires that are no longer good to use on the street! Old tires are perfectly fine to use on a trainer as long as you clean the tread and pick out anything embedded in the tire.

A trainer adjusted properly will not have bits of shredded rubber dust laying about. In that same vein, nor would a properly adjusted trainer that is a higher quality unit deposit it's aluminum or steel on the roller onto the tire giving it a sheen.

My Cycleops Fluid 2 is a steel drum not aluminum. I've used it now for 8 years and there's no groves on the drum, and no signs of wear like grooves, there's also no rubber fragments on the drum either.