Pixhawk Quadcopter Flipping to Right on Throttle Up!

Hello!

I am setting up a Pixhawk-powered quadcopter on a Tarot 650 frame. Using SunnySky X4108S 600kV motors, Velotech Magic 30A OPTO ESCs. I am currently having a problem where the quadcopter wants to flip to the right (roll) when I throttle up.

I have tested obvious things such as recalibrating the ESCs, motor spin direction, prop installation, recalibrated the Pixhawk compass -- and to no avail. My radio channels have been calibrated in Mission Planner and respond as they should when I give stick input.

In ESC calibration mode, all motors accelerate at the same rate (when the Pixhawk is passing raw PWM), but when I boot it up normally and throttle up, I notice the motors on the left hand side of the quad (facing forward) are louder and sound like they are spinning harder. I have some images taken from the motor failsafe/calibration screen showing what is happening:

http://imgur.com/a/2Ip5y

I am not giving any pitch/roll/yaw commands and yet it looks like the Pixhawk is trying to do those things. My RC map is as follows:

RCMAP_PITCH,3 RCMAP_ROLL,2 RCMAP_THROTTLE,1 RCMAP_YAW,4

This was done to match the channel mapping on my FrSky Taranis X9D Plus.

This quad has worked before with a different owner, I did make the mistake of upgrading the firmware, clearing settings and setting it up all over again (ensuring to take a backup of the previous owner's stock settings), copying over relevant settings from the last install.

I figured this might be a compass/level/calibration issue and have recalibrated the compass many times but since it is so hard to spin such a big quad on every axis, I have done this with the Pixhawk taken off of the quad and on my desk.

I have logs from Mission Planner along with my complete settings list here:

http://alaskafpv.com/Tarot650Logs.zip

I am really at my wit's end now, I might be missing something completely obvious at this point. I've spent quite a few hours over the past two days trying to narrow this down so any help is GREATLY appreciated at this point.