The splash screen bug is indeed gone! Thank you!
I still have to right click to get it to respond to my graphics tablet... at all now. Fixing the splash screen issue seems to have reduced my issue to "the drawing area doesn't respond to my tablet until I right click" and it seems to work fine with my touchpad. Though if I move between the two it will make a line between the beginning of whatever I'd last drawn using my tablet and wherever the mouse is pointing when I click with the touchpad.
I'll keep checking further updates in case the issue gets fixed, but for now I'm going to stick to 0.6.1
Graphics Tablets DO interface with programs differently from mice. One of the big reasons I like Pixelorama is that other pixel art specific programs I found would not respond at all to my tablet's clicks. So like, this is a huge feature with me (and if this issue is sorted, you could advertise 'graphics tablet friendly' as a feature).