A: No clue
A: A 7/8" arbor has a 5/8" nut. This disc fits in place of the nut.
A: Should do that job with ease...may require a few of these if there's a lot of ground to cover.
A: It might scratch the tile.
A: yes, but you will likely damage the glaze on the tile
A: I would test one one a piece of tile to see how it might damage the tile first. You would need to be careful around any grout.
A: You could but, you will probably also remove any finish on the tile as well. Something a little less abrasive would be better.
A: Thin gauge sheet aluminum it nights not be good for. But thicker stuff (14 ga and up) it should be fine on if it's rigid.
A: Not a thick gauge aluminum. If its thin siding, you may dent it as your press in.
A: I did not have any problem with it. You do need to be aware of the amount of pressure you use. Worth spot testing...
A: It should be fine as long as you don't try to get too aggressive
A: I have had great success striping paint off old pine boards with minimal scoring on the wood - your harder aluminum should be just fine (it isn't as aggressive as coarse sandpaper, and the paint doesn't load up as sandpaper typical does). Good luck with your project!