My 5K iMac lasted 2 years before the logicboard crapped out. Definitely didn't keep going and going.
Just did some video tests with Moment. It's nice...but ProCam is free and does just as well and has most of the same features.
Great writeup. One thing though...you mentioned that you can use DJI Focus motors for manual lenses. I was told directly by DJI support that the current DJI Focus motors will NOT work with the Ronin S, and that they are in the process of making a new focus motor for the S.