I have not done this specific test, but based on my experience with a 4K webcam, I assume it should be possible. You may also need a USB C charger that provides an extra power supply to the devices (in this case the Blu-ray burner) on the switch.

Unfortunately I cannot answer this question. I need this switch to operate 2 PCs with one screen, the same keyboard, mouse and webcam. This works perfectly.

In my opinion it is not possible to change during burning, but without changing the source it should not be a problem.

For keyboard and mouse it works perfectly, for other devices I can't say anything - sorry