Besides the site not rendering at all on some (important!) browsers, cut'n'pasting text also doesn't work: spaces are not included.

Are you sure you couldn't live with "text-align: justify; text-justify: inter-word;" and lang="en"? If you can't, maybe just make separate PDF downloads of your articles, if you want to control the typography in this kind of detail.

And if OP is interested in improving the typography, a trivial, side-effect free improvement that’s currently missing would be to replace dashes and quotation marks by their “proper” glyphs, and using non-breaking whitespace where appropriate.

the font loader script is causing it to never load for me

i run latest chrome with the --disable-remote-fonts command line option

I've added a timeout on the font loader, you should make it through after a few seconds, although I don't know how good the page will look without the custom fonts.

I've also added a transpiler.