Agree with you about that UM is not coming with a great touch screen support xD
I got one touch device a bit bigger than yours and made a guide how to make good usage of touch screen inside here 
: ( for touch geastures, orientation, ...)
About your touchscreen that do not work after kernel upgrade, I think, you just need to compile the driver of the touchscreen again - Got same issue with my broadcom wifi & bluetooth combo card - need to manually action after each kernel upgrade.
P.S Dreaming to have same device as you