Made below commit on ONE branch:
Regarding Fail #1, I followed these steps, without installing the driver of course, simply downloaded, extracted and installed the xinput-calibrator deb file and run the calibration tool producing these:
Section "InputClass"
Identifier "calibration"
MatchProduct "ADS7846 Touchscreen"
Option "Calibration" "254 3910 3716 1476"
Option "SwapAxes" "1"
Option "InvertX" "1"
Option "InvertY" "1"
EndSection
and copied to /etc/X11/xorg.conf.d/99-calibration.conf (replacing old entry) and it seems to work fine now. I doubt this will work on both you and me. Not sure what to make of it if you tested on the crowdfunding campaign LCD which is what I (only) have here too.