hehehehe Thanks for the prototype thoughts

As for the editors, etc. My answer here is to have an idea/goal and a thought on how to get there.
Think of everything like lego. each thing is just one little block. and you can put together the little blocks to make bigger things.
So you will first need a gui system - I wrote my own because I had a very specific set of things I wanted to do. Once you have that you need a basic window system to plug them into. That probably need some from of character (bitmap) font. so you need a way to edit the font... once you have a font system you can build a tile system that eats the fonts.
using the same basic principle you can build a 3d editor. but what about texturing? Unwrapping and texturing is just so tedious, and having all those multiple textures for models will drag a game down - why not use the character font system you previously created - and just apply the characters as textures and then reuse the same font for all the textures on all models? Now you have only one texture and no overheads with texture space...
so... Taking the image above. There is only one simple texture being used for all the models! The UI is really just reusing all the gui bits |I already had lying around
And on it goes. this block begats that block...