My tile backsplash was installed after the OTR MW was installed, so there's no backsplash behind the MW. Read the installation instructions carefully with the new one, some of them have to be installed higher than your old one, especially if you have a pro style stove or cooktop.

DH just pulled off the old backspash and wall board, he's down to studs. We are putting in a microwave with vent over the cooktop. Should the backplash tile come all the way under the microwave (in case we replace)? He is planning on venting straight out the back - so will the tile guy tile around the vent? Is it better to vent through the cabinet above? I'd rather not lose the space. ...Uh oh... I just heard a crash and a cuss word from downstairs...must be a problem with the counters he's removing...

Have a granite fabricator cut off the extra granite there, or you can’t make the bracket hang evenly. Keep the piece. Then drill the wall without granite. A small job premium and specialty skill set means that you’ll likely pay $200-$400 to have that done. Look around at the rest of you stone and see if you have any vhips that need filling, or smoothing out. Or look at your bath vanities and see if you’d want to replace any. If you can make it a bit bigger job, you’ll get a bit more bang for the money spent.

The better idea is to remove the backsplash tiles. Otherwise, you get the proper bit and drill a hole through the tile, then screw into the stud(s). Not drywall screws. They break. Probably a good wood screw at least 2" long, whatever the directions states.