Flooring Tile - HELP. Replacing kitchen tile floor & tile backsplash

I need some info on what I can expect when I demo the existing tile floor and tile backsplash in my kitchen. The tile floor is set over plywood subfloor and the tile backsplash was set on drywall. Is there a significant chance that I once I remove the tile flooring, that the old mastic/motar will be difficult to remove from the existing subfloor? If so, I imagine that I'll have to use a floor leveling compound to smooth the subfloor before laying new tile? Same question for the tile backsplash... Is there a good chance that I'll damage the drywall when trying to remove the old mastic? Any info./personal experience would be greatly appreciated!!!

I had to replace the tile around our fireplace once. I was pulling my hair out trying to save the drywall and Luan, on the floor. My job jot a lot easier when I just planned on replacing them both.

Hope that helps