thanks Mike that is super helpful! There is just so much to learn all at once.
I wonder if you would mind looking at these pics of DX6 Channel Assignment. It all works right in radio calibration - but it seems like a complicated and un-intuitive way to do it so I wonder if there was a simpler path. It seems like the default naming convention in the controller just doesnt match how APM does business (which is fine as long as I am safe). Also I don't think this is really covered in the wiki, and is not at all explained in the DX6 manual so i had to do some reverse engineering.
I've got an older post as well that only I have replied to (and im super impatient). It is a question not a complaint - maybe these boards are too developer focused or high level for me. DIYDrones looks good too.
For future users looking for a simple answer:
this page of the wiki describes radio calibration including directions:
Reversing is not done within mission planner but within the transmitter. For DX6 - go to Servo Setup and change travel to reverse, then reverse the fields as necessary.
For my setup I have had to reverse Yaw, Pitch, and Roll. According to the wiki, on the radio calibration screen all of the bars should move in the same direction as the controls sticks EXCEPT for pitch.