Lightburn glitches (slow, image shifting, etc.)

That is typically caused by communication dropouts trashing parts of the file, so the USB link is the main suspect.

If the USB cable is more than about a meter long, then it’s definitely the cause.

All of the problems you mention can be caused by bad communications, so:

However, for a machine with a Ruida controller, using Ethernet instead of USB cures a wide variety of problems: