No offense, but this is nothing new. Sonic GL, Sonic Bastardized, Sonic Genesis, Sonic Ashura Dark Reign, Damizean/Mark, Sonic Point of Action, Athimator's Sonic BGE, and all major 3D games engines use ray casting for collisions (and slops).
Quoted for the truth.
True... but then why don't you just use pure C++ and save yourself the trouble of using GameMaker?
Well, it appears that you put a great deal of work into your engine and it is good for a GM game. However, nothing that have you mentioned is "new".
Then why do you use it? Please, look around at better engines that are designed for 3D games. I strongly recommend that you take a look at the Blender Game Engine if you want to make a 3D game.