Great questions!
1 - My primary concern is with generative AI rather than assistive AI. Using AI for spell check is fine. I find it funny that you want to remove the “impolite” parts! The way you speak is the soul of your creation, so it feels sad to lose that by having AI remove that soul and make it more generic. For something like that, it can be quite fun to ask a friend to read over your words and help you figure out what you need to edit. As for translating it to different languages: AI is still very often incorrect. It will do no favors for anyone with a poor translation. And for a game about geography, it makes the most sense to involve people who speak other languages! Join some indie game discord servers, and I’m sure you’ll be able to find someone who wants to help with translation.
Ultimately, the answer to your question about AI is that you must use your own words. You can use AI to help you organize your ideas, but don’t copy+paste anything it says to you. This is your project that you are creating because you love it, so believe in yourself!
2 - You still completely own your ideas! Your game will be sold for a charitable cause in this bundle, but there will be nothing preventing you from selling it elsewhere, even here on Itch.