Yes. Go to Settings → Input → Peripherals → CEC and disable it.
It is possible, and usually yields faster response times.
There’s a few discussions here:
Yes – it should work without issue.
You shouldn’t need to tweak anything here.
You probably want to set 10-bit output via command line. As you are familiar with SSH, this shouldn’t be tricky.
We are working on an auto-switching option, but it’s not quite ready yet.
Sam