@karmacomposer, if you're interested I could talk you through creating a simple level and publishing it. That way you'll see the whole process. Send me an email michael@schmidtworkshops.com or we can just discuss it right here if that's easier.

For the record I do not use .wad files or BSP maps at all, though I do know how to. Also, I think larger levels are one of the tougher challenges I have faced with this engine. For my space exploration game, I have been able to get fairly big outdoor levels, but it took a lot of manual optimization, and they are still pretty small compared to other modern games. I believe larger levels can be made, but I think it will require quite a bit of clever scripting to keep the number of objects low, especially for grass and plant objects...