Okay, so I've been playing around more with my Pro 3 and have deduced that this may be a software-related problem. I also noticed both the left and right sides of the screen near the bezel do have a slight amount of ripple to them, most evident during the "Surface" startup screen. Along with the request below, I'd really appreciate the help from anyone reading this who can spare ten minutes of their time.
As I wrote above, I noticed this issue when finger doodling on Sketchbook Express. You can see that there is a portion of the screen below the power button's location that seems to not register touch input like the rest of the top edge. If you may, please install/open this app and try drawing (with your finger) a continuous jagged line from right to left, making sure to cross the bezel and screen with each go. Does yours end up looking like this?
Next, try installing/opening Fresh Paint. Do the same drawing with your finger again. When I did this, Fresh Paint had no problem creating the line I wanted pretty consistently. Please let me know your findings.
And for extra credit, please let me know if your screens have some ripple to them in the areas I described. I really appreciate your time and efforts. I went through a couple of screen recalibrations (thank you for the suggestion, smoheath) and even did a system refresh. Just trying to ease my mind that my $2,000 tablet isn't operating as it should. :)