Those results definitely seem to be pointing towards an issue with the touch part of the touch screen. One more thing you can try:
In the master branch, make the same change to remove the checkTouch call, then see if you can operate the radio. With any luck, you'll be able to actually move the white border cursor around now, so even if you can't use the touch functionality, you should be able to access all features. Since you have a new arduino, you'll need to recalibrate the radio from the setup menu. Ashhar made a video demonstrating this, which is roughly the same procedure for my build, but the menu is the gear icon, instead of a long press. https://www.youtube.com/watch?v=t6LGXhS4_O8
If that test checks out (radio is working, less touch), then the next thing to do would be to replace the touchscreen module.