I know you're already getting piled on for AI art, but one thing I would suggest, in the future look for free assets on itch! It can be beneficial to both you and the artist.
Unfortunately I don't have anyone to play with at this time, but it comes across as being a little too vague to me. I do like the scenario builder guide, but something like the Enemies section just feels incomplete. Maybe some premade enemies and bosses, an example of how items would be used (you mention an inventory and have a sizeable inventory on the character sheet), etc. would make it feel more complete. Personally, I think things like this are incredibly hard to balance anyway, so commend you on trying it in such a short timeline!