Ah. I didn’t address the moving window part. All I can think is sent data includes a scankey code to Grab Window. I use XFCE and it has ALT + Right-Mouse-Drag to move a window. I’m not sure how that would be fixed.
Additionally, while you are frustrated, try to refrain from cursing or swearing when asking for help.
The firewall solution would certainly work on a trusted LAN, thanks for the suggestion. As a proof of concept GfxTablet definitely succeeds in demonstrating that we have are carrying functional drawing tablets around with us every day. Thanks!
I had the same symptoms. Try the changes to the code I made in pull request 95. It uses a newer Linux API to register the device, and libinput seems happy with it now, so it works in gimp and inkscape.