1) never experienced any lockup and I'm doing lots of GPU- and CPU intensive work (editing, cgi, compositing, colorgrading etc)
2) Wayland is pretty much beta still - things may change, but Xorg honestly works really well here
3) Kwin sucks - even using Intel hardware Chrome/Firefox scroll slower and with more lag than even using mutter (which I'm using a pre 3.32 version of), desktop animations seem smoother though.
No glitches after sleep either - even Resolve Studio keeps running
4) They have forums with active developers at nvidia.
5) Using Prime on my Laptop on Manjaro and it has been tearing-free so far, but again on Kwin it's a mess though sadly.
6) My distribution handles that. Have been using Manjaro for a few months and never had any issues after updating.
7) My GPUs are running fine so far (1080 Ti and 980M GT), but that would be bad for sure.
The AMD Vega VII looks exciting though. 16GB of insanely fast vram should speed up Davinci Resolve Studio a lot. Still waiting for Linux/Davinci Resolve Studio benchmarks though.