"I'm not using the APM, just the IMU for a different project (GPS blimp). On the IMU it says Vin>6V so that makes me think the IMU has a voltage regulator also? Is that not true? I'm going to use a 5V regulator to power the servo now."
"Also, if I want to run a servo off one of the PWM pins are there any pins on the board that output enough current at 5V to power the servo or do I need to use external power?"