1. I am using 140 oz in servo for rudder on that plane. I learned the hard way after a 90 oz in servo went bad on me. I am also using 6 volts.

2. That propeller is a dog. The APC will give you lots of RPM/thrust which is critical here too.

3. Your CG sounds O.K. I've tried going farther aft but precision aerobatics get very hairy on windy days.