Great question. I don't think I mentioned anything about stat recovery (resting, healing, etc...). I would say that when any stat reaches 0, any successful skill check can not recover back any stat points. A player has only a 10% chance of being successful and should really just consider themselves lucky if they roll a 1 on the d10. I say healing/stat recovery from 0 can only be done when combat is over and from a safe location. I have updated the file and mention this under Notes. I also added the Defender class :) Thanks for catching this!
If you like this mechanic, while two totally different games, I suggest you check out https://www.drivethrurpg.com/en/product/440073. It's the first game I read that allows for players to "burn" their stats.