The latest stable or just YOLO with the latest alpha? I'm asking 'cuz I've just loaded up the latest alpha and I'm already getting 3 errors because 3 ".png"-s are missing. Did a bit of google-ing and people suggest avoiding the alpha and beta builds. Any wild thoughts?

For a game jam, I would just stick with whatever version you are familiar with.  You don't want to be spending a lot of time chasing down issues with engine bugs when under a time constraint.