Dragon's Den... It's gonna happen

From what you've posted so far, everything outside of reallocating and building the actual maps requires editing events to some degree. Zone Eater wouldn't be event editing, though that was already covered above.

Disabling access to certain places can be as easy as removing the pointers to the events, which generally entails preventing certain event bits from getting set. This is information you'll need to extract from the event dump and event bits listing.