I recommend starting small and working your way up to that idea. It's a good idea and doable, but best to walk before running.
I'm in the process of doing the same thing you want to do and there can be a lot of work involved in getting it going.
in my editor you walk around like you are in the game then press q to load a model from file, then you can zoom out and stamp/rotate/scale the object as many times as needed then zoom back in and walk some more.
id start with TDK's tutorials to help you understand the basics.
if you want to load models into your editor, then I would look into bbb gui as it has a command for open/save dialogue which is very handy.
also look into the pick screen command
then there is saving. you can do it yourself with the native file commands, but i personally use dark data. its just easier for me, but there is nothing wrong with native commands.
if you want to edit terrain I recommend the paid version of Blitzwerk terrain because it is easy. but there is no reason you couldn't edit a jpg and reload it as an advanced terrain.
outside of these suggestions all i can say is break this project down into smaller tasks and conquer them one by one, then as you build a collection of studies for various aspects of your end goal you can piece them together. soon you will have some thing that is beginning to resemble your goal.
good luck!
kezzla
Sometimes I like to use words out of contents
