The super sensitive touch pad is a problem I have with my laptops. I never use the touch pad but I rest my wrists on either side of it because the desk top is much higher than the height of my elbows when I sit. Over time that has pressed the touchpad down a little and made it click when I was nowhere near touching it. All I do is roll my wrist the wrong way and something clicks on the touchpad. And most of the time that phantom click closes the tab I was on. No fun.
I have no idea how you got drawings saved onto the desktop wallpaper from your pen and paper doodle though. That is a new one to me.
Or do you have a touch MONITOR as well and never knew? Which does not help much either but may explain why the two touchpads 'talk' to one another.