It seems with DJI there's a small element of luck whether or not you end up with a bad unit or not unfortunately :/
I fly a combination of normal orientation and of course lock in the cases where I want to do a rotation at the same time.
I haven't done any fine tuning, in fact we haven't been able to connect it to the computer just yet, possibly driver issues, not sure, it works fine without connecting it. I have changed the tilt limit inside the NAZA side of the gimbal control so that it doesn't tilt too high or low. So yes tilt control is hooked up, though we haven't done a lot of in filming tilting, only minor adjustments between shots as it is hard to do without fpv.
Depends really. Lately (and in this video) I've been shooting 1080p 50fps with protune on. Protune with 2.7k can look good but I personally don't know how to deal with it I'm post as far as sharpening it and grading it. I'm hoping to learn that soon.