I don't really see what GM lacks in collision support that you'd need... it's really nothing like clickteam products. You wouldn't be working around or abusing anything, this is pretty much what GM is for... platformers with bitmap collisions.
If you don't want to learn the engine, fine... I guess you'll have to wait for a coder to appear.
If you don't want to learn the engine, fine... I guess you'll have to wait for a coder to appear.