If you are worried about the motor, go down in prop size. You might as well, since it sounds like you have more power than you really need, anyways. Also, in the AZ heat, it is important to land every few minutes to let the motor cool down. I also let it sit in between flights to let it cool completely. I may just be paranoid, but I would be so mad at myself if I burnt up my Hacker because of something that could have been avoided. Good luck, and have fun!

Dan