But I also doubt I could produce all of these shapes in Blender. I would have no idea how to do these, for example:
If the goal is to end up with what you pictured in your mind, then it's absolutely horrid.
BTW, part of my problem with Blender is that I -don't- know how to use it. I tried several times on the previous interface and gave up each time. The new one is better, but I still haven't used it enough to have any confidence that I know what I'm doing. So I consider it an apt comparison.
Here are some that are mostly bilaterally symmetrical, but with left-right asymmetry.
http://endlessforms.com/o/60967/ (mad hatter)
http://endlessforms.com/o/39225/ (Dr. Evil)
There are some with no symmetry at all....
However I haven't had any problem with any of the other three.js demos, or any other work of its creator, Mr Doob (like Google's Rome).
If possible, can you DM me your IP on twitter, so I can see where in the logs you showed up? If it's weird giving out your IP to random people on the internet, you could just visit endlessforms.com / DanielRibeiroDebug , and I'll find the 404 in the log file.