Okay, I just tried Superman to skate to roll chin to shoulder, a bunch of times, earlier this evening.
If I held my breath until I rolled chin to shoulder, I got air.
If I exhaled at all first, such as to clear my mouth and nose of water before inhaling, I didn't consistently get air. Sometimes I got water. Sometimes my face never broke the surface.
If I tried to get a few breaths, my face would often sink below the surface when I exhaled.
1/ I caught myself lifting my head once. Otherwise, I don't think I was doing so.
2/ I don't think I was tensing my neck. I tried to relax it.
3/ I'm not sure that I understand what you mean by "over-rotation." Sometimes I turned my head. Other times I went to sweet spot, or even to flat on my back.
4/ I wasn't even attempting to raise my recovery arm in any of these breathing exercises. I kept my recovery arm by my side with my palm on my thigh.
I want to avoid what some call "stacked breathing:" breathing in without expelling stale air, to the point that one has lungs full of stale air yet breathless. But if I exhale very much, I sink and can't breathe.
Re video: I don't think the pool permits the filming of videos. I'll see if I can confirm this.
I'm not yet to the point of taking 8-12 strokes. I'm still working on the basics: finding sweet spot, superman, skate, skate switch, etc.
In the bigger picture, I can tell that I'm making progress in terms of developing skills, but actually having fun is still elusive. It's tiresome getting water up my nose into my sinuses, and down my throat to make me cough and gag, and struggling with all of these skills. Sigh.