I'd love to have the option to use something OTHER than the aggravatingly cryptic uselessly forgettable and often "just gets in the damned way of normal typing" markdown in favor of something like bbCode. Aaron and I may have been close friends, doesn't mean I don't curse the day he unleashed that train-wreck upon the world.
Something he regretted in hindsight even having been involved in creating.
I would be far more likely to write even more often here and in a much more complete and involved manner if markdown wasn't the only choice for formatting.
The willy-nilly mix of font-sizes, inaccessible font sizes, inconsistent scaling, and mix of pixel metric media queries with elastic font sizes could stand to be fixed too -- I've got about 1k of custom CSS i'm applying with stylish now to even get pages usable. If you're going to use relative font sizes, your media queries should match and not be in fixed metrics -- remember, pixels is for morons who don't give a flying purple fish about users. The WCAG says to use EM, so use 'em!
Hence opening the content column up to at least be semi-fluid might be nice too. It's aggravating as a large font / non-standard font metric user to end up with a content column so narrow it doesn't even hold a dozen words on average per line.
Likewise pick a damned font-face... PREFERABLY not a serif one since on screen media unless you have a HDX/retina/4k display the extra doo-dads on the glyphs compromise legibility. Fine on my workstation with +30% zoom in-browser and 24px == 1em as the system metric, useless illegible crap on my 800x480 netbook or my 1366x768 tablet.
Say it with me people, sans is for screen, serif is for print!
Lightening the page-loads to better leverage caching wouldn't hurt either. STOP inlining SVG that could be cached in the bloody markup... STOP using the fat bloated SVG for things you could store in a font file. Make page loads faster/smoother with less overhead and you'll get more participation.
Some better scripting off graceful degradation would be nice. I've said it a few times and I'll say it again -- I know a number of developers who would fit right in here that won't even TOUCH the place just because scripting off this site goes bits-up face-down... and there's NO reason for that. You can't sign in, you can't type responses, and navigation is busted... when the only content of the site is TEXT.
Likewise better semantics to help in navigating the site wouldn't hurt. You've got multiple H1 without "section", H3 that aren't the start of subsections of the H2 preceeding them, etc, etc... leading to a site that is grammatical/structural gibberish on things like my braille reader.
Remember, unless you use HTML 5's SECTION tag, THE H1 is THE heading on every page that EVERYTHING on EVERY page is a subsection of -- hence the site name typically being the candidate for that. Opening SECTION (or ARTICLE) resets you to H1 depth. An H2 is the start of a major subsection of the page... and H3 is the start of a subsection of the H2 before it. An H4 is the start of a subsection of the H3 preceding it. Care to guess what H5 and H6 MEAN? Likewise HR means a change in topic or section at the paragraph or H2 level. They do NOT mean "fonts in different weights and sizes" or "draw a line across the screen" -- and if you are using them for that purpose you have failed to divine the intent of HTML. JUST as having a H3 without a H2 before it is broken hard to navigate gibberish.
Much like the garbage incomplete scripted trash for forms without actual FORMS, FIELDSET, or LABEL. For the love of Christmas PLACEHOLDER is not a LABEL!
Then people wonder why I say most folks using fancy nonsense like frameworks aren't qualified to write a single line of HTML.