You could but, you will probably also remove any finish on the tile as well. Something a little less abrasive would be better.
It should be fine as long as you don't try to get too aggressive
It is ideal for that purpose. That is exactly why I purchased them. I had a 8' x 10' floor that was painted and I went through two discs but got all the paint off.
yes. see the rated speed on the discs.
they screw onto a 5/8 threaded shaft.
They come as singles at Home Depot.
It is a sponge like plastic like a Scotch Brite impregnated with abrasive material. Not as dense as a scotch bright though.