cool! I’m going to try to make a game using the software that you used and I just wanted to see how long it took for you to do it. Thank you for answering!
you can't delete maps unless it's the most recent one, but you can delete everything about the map so it's restored to a blank slate. I think it's in "delete map data" or something but I can't check because i'm away from my computer for a few weeks. as for transporting heroes, you can simply use doors! if you need any more help i recommend signing up for the Slime Salad forums or discord or consulting the OHR wiki