1. yes!
2. no! as long as you are inspired by the jam itself, your submission is welcomed.
The influence for them was the movie The VVitch, hence the subtitle "do you like the live deliciously?"
The idea being that they are higher powers you can worship/petition. So instead of the traditional Cleric role, anyone can choose to follow one and live by the principals of that being. But they are also left rather open so as to inspire people to take them and run with them.
So there is no "canon" for them. Yet. I'd have to run a game where a player reached out to one to really figure that part out.
That's something I can work on if I find the free time to do so. But until then, some of the great people in the community have made some. If you join the discord they've been made free to download.
https://discord.gg/QSQsKRyeYz
Hey, as for the last question: I'd let them add dice whenever they wanted, simply because that could be super tense. But it's totally fair to limit it to only before.
As for the monsters: yes, monsters roll 2d6+ whatever their attack modifier is. Tho, honestly, using the HD as a dice pool could be really fun. There's probably a cool hack in there.
I think it'd be easy to run solo by following the one-action-per-section-of-time rule, the bingo cards, and then a dungeon you want to explore. If you wanted to ask some other folks, check out the discord! https://discord.gg/S4EdzAjfn2