I have one, I don't think your calibrating in loitor mode, GPS isn't locked on.
Your props should all be the same length. The screw on DJI props work fine. I use the originals
Yes theirs a lot of information on RC.groups, but the users aren't very helpful. I had better luck with google.
Try this
Arming outside of Manual Mode
Set your switches to Loiter. If you carefully look at the Red light, you will notice that it is blinking twice, pause, then again. It is hard to notice, but look for it. When it is blinking twice like that it means that it is still waiting on some pre-arm...