I use a 14px bitmap font as part of my system theme. It is set to display at 14px in my gtk theme which works for tabs, bookmarks, right-click menus, and other parts of Firefox UI, but the Firefox address bar doesn't seem to be the same size and is blurry.
How do I change the font size of the address bar? Is there an element I can target in userChrome?
You could specify the element you want to modify with the Firefox browser toolbox:
https://firefox-source-docs.mozilla.org/devtools-user/browser_toolbox/index.html