I’m working on adding Spheres, but for some reason nothing rendered when I tried rendering it. After I get spheres done, I planned for cylinders. Custom vertices selection & movement, and revolve/extrude sounds cool, but might take a while to get in. I think I’ll actually add shader support in the next update. I was thinking about rotations a while ago, too, but I’m still thinking about some of the equations required for it.
@SkyTheCoder- Jmv38 did some cool tutorials with spheres here (halfway down page, look for earth movies), they may help
I actually used some of spacemonkey’s sphere code for it, but I couldn’t figure out why it didn’t render anything. (Not just the sphere, but any boxes, too.) It was working as a textured sphere in another project.
Tricky stuff, 3D, it might be right there just behind the camera where you can’t see it!
I actually though of that. I tried scaling it down on a size of 10 and nothing appeared.
Try looking behind you. A lot of my 3D stuff started out there 
Actually, if you haven’t included it already, I’d give yourself the ability to look around and up and down, maybe with parameters. Then you can see if you’ve misplaced your stuff!
If you’re still looking for one, I have a .stl file importer I’ve been working on. Also, check out a post i may or may not have put up a while back that does a similar thing to what you are doing. It creates surfaces from equations. The equations have to be hard coded into the program… For now! But let me know and I will post my code 
Here is my parser for the ascii OBJ format:
https://gist.github.com/tnlogy/4690383
To create an 3d modeler it would be nice to build it with my translation of the CSG.js code.