Thank you for the thorough feedback and I'm super glad you're enjoying the game! :)
Unfortunately (because I'm a fool) a lot of this game was made without as much foresight as it should've been, so there's a lot of outstanding issues with some of the interactions that aren't super easy to fix (such as the ground texture resolution and seams) :(
However I'm currently working on a sequel which will provide more opportunities to explore around and addresses both the ground painting issues! The eraser ability might prove more difficult since it would result in a bit of a change from how the paint system usually works, but I'll definitely investigate it to see if it's something I can work into the sequel as well.
Thanks again!
-Devon