Thanks for all of the suggestions and feedback ^_^
I fixed up the issue with selecting level 9, it now properly goes to level 9 instead of ending the game (Idk how I missed that but thanks for mentioning it lol).
Here's some tips for the purple button: The line that changes from purple to white instead of purple to red points to the next door that'll be disabled, while all other doors that the purple button connected to previously will be re-enabled even if another button turned that door off. This allows for some interesting interactions with other buttons that connect to the same door as one of the purple buttons which is seen in level 4 and level 9 (I'd say that level 4 is a better place to go and see this however xd).
I hope that clears some things up about how the purple button works, I'll see about adding clearer instructions to the way each individual button works sometime after the game jam ends :)
Also I'll look into adding in your other suggestions after the voting period for the game jam ends as well, those would be pretty good additons to the game and would definitely help with level 9's confusion lol. Thanks ^.^