I've reworked my script to make it quite a bit more flexible. As part of that it has become two different scripts.
I haven't yet had time to write up a how-to for customizing website-specific output from Pandoc. I hope to do that over the next week or so, and to push out a few more website-specific formatting rules.
I'm mainly only doing this to meet my own needs (other tools just weren't cutting it for me), but if you do give it a try, feedback and suggestions are welcome.
You can see the latest iteration and follow future developments here:
https://github.com/0r0/klemheist