1) You'll probably have to get a wireless receiver made for phones with non-removeable backs and that plug into the charging port. Of course that leaves the port open during charging, and plugging the receiver's plug in and out kind of defeats th whole idea of wireless charging.
2) There are always carbide particles in the air. Would you rather scratch the glass on the phone (it's only 6.7 hardness, carbide is 9, so it will scratch Gorilla Glass 3), or scratch a <$2 plastic screen protector (you can get them 3/$5)?