Read your thread/link. It's funny, I already do something like that, too, with all the meta-data. More than what you've got. Anal-retentively more.
'Course, I'm not using Calibre (yet.) And the utility I use is my text editor, not a pre-processor to call Calibre... I think what I'm shooting for here is a utility/software/reader neutral way to present an ebook in simplest HTML -- consistency being the key. Then anyone can take it and convert it pretty easily. Heck, you could use it for your h2lrf, almost without effort -- just a minor change to the meta you look for.
As for the CSS macros -- I think what I'm talking about is that each ebook reader (hardware) should probably have its own CSS, right? I mean, what looks good on a 5" JetBook, probably doesn't look as good on an 11" DS1000. So you'd want to answer a few questions in a dialog (well, I would) about what sort of reader you're trying to make an EPUB for. Then, boom, CSS created. Maybe it calls some common defaults in a common.css file or such.
Now that I re-read my thoughts above, I think I'm talking about two separate things. Common, single CSS will be all that's necessary. Later in the process, when I want to make a package for a hardware reader, then an additional CSS macro might be necessary. You're right, as usual pepak.
Anyway, gonna dig out my old Barsoom folder, and grab A Princess of Mars to use as an example for the next stuff.
m a r