As you can see I do not care for mirrors all over the place either. Replaced with even larger collage frames in this picture with family pictures and places visited.
The glass panel mirrors can be removed with a tile spatula, thick blade, use a 1/8" piece of wood panel to protect the wall when you slip blade under mirror surface and pry off mirror, and wear goggles.
I would place a sheet over the counter area in case the mirror shatters. If your careful they should pop off wall surface.
Clean up wall than place your tile.
Some of the newer MH's have tile in place of mirrors and you can use all kinds of decorative ideas. Good luck with your project.