Wow, if just the school and county rate was 6.85% that's crazy high and explains the insane taxes. For perspective, my total property tax rate here in West Hempfield is 22.1189 mills, or roughly 2.2%, and that's including a municipal rate of 1.95 mils that I'm not sure you were even factoring in. Wonder why they are so high up that way.
I always tell my wife you never truly own your home, even after paying off your mortgage, and if you think you do, try not paying your property tax bill and see what happen haha.