I'm note sure for touchscreen calibration, here's what happened to me:
I booted with a non-functional right nub (from previous hardware bug) selected "yes, calibrate" by mistake, and while clicking the little targets, i made a double tap, so i missed totally the configuration, leading to a unusable OP.
Of course i know that the pandora button opens the Xfce menu, and space is the left click, but it's not a good thing to happen to new customers.
I suggest a new check after the calibration, like "Is it ok or do you want to recalibrate ?".
Also, i found the new default nub cursor speed awfully slow.