If you get reverse when you adjust the trim I would suspect a calibration error or the throttle deadband could be too small for your radio. If the ESC has trouble sensing neutral, reverse and brakes may not function properly. The Castlelink definitely makes it much easier to know what settings you are using.

I usually recommend the maximum EPA adjustment your radio allows before calibration. I believe yours will go up to 125%. Of course you know to start with throttle trim at zero.