would be possible but i don't like the idea of a small white window opening every time i open a level (except one is already open)

i don't understand neoaxis (the engine is pretty good but i have no idea how the core works)

I tried Axiom, but the samples didn't compile...

Also a lot of other free 3d engines don't fit my coding style and code requirements (this is just personal but i really hate bad coding style)

But i've done some other engines before and the worked really good (except my OpenGL renderer, but that's another story)