I recommend using #12 drywall anchors if you're not mounting on a stud. You can use the same screws that the stock stand mounts with to attach the AMS. Mount the adapter to the wall first and then attach the AMS! I printed in PLA and it's fine so far, but given the potential weight on the system, I'd recommend printing this in PETG! Both parts can be printed at the same time on the A1 Mini :)