i feel like i missed out a lot on bluzone :(
godspeed on this project. and this time around see if you can do larger, more open terrain build. if you're going to hit 100K brickcount anyways, you should do it open-ended.
I suggest setting the adventure on an island so there would be bounds to the terrain while keeping it as open as possible, without forcing you to use awkward cubescape bounds. but since you already started, its a bit late to suggest this...
i guess you can handle the storyline yourself but if you need ideas/help just hit me up in a pm and i can throw ideas at you.