Oh, wow. Would you consider letting another group of devs look at it? I'm not sure what we could do in return, but having access to something that's further along than our own engine, even just for reference, would be incredible.
Thanks. I've been playing around with making my own engine for a year now. It's not something I'd release to the public, but I'd use it to make all of my future games. I won't be finished with it until next year, I'm making a Pokemon Structure Kit in GameMaker this year. 3 months in development so far and still need a lot of work.