Thanks for all the informative responses; that's a lot of good reading.
That being said, it's a shame when people waste so much time, talent, and work trying to copy someone else's work. Especially when they do a good job, and could have had an awesome project of their own.
To be honest, the engine and its editing tools are my project, which is where my real interests lie. The game is just a "case study", if you will, to stress and test the sanity and flexibility of the engine.