Bingo... I should have thought of that. It is my template (the popular Flex commercial template), which does some messy stuff with FontAwesome, as it turns out. In case anyone else out there is using Flex, you want to check out the ../public_html/templates/flex/css/font-awesome-v4-shims.min.css file and comment out the stuff about fa-pencil and fa-shield pseudo class (:before) declarations. I'm not sure if any other icons are affected at this point, but at least I now know where to go to nix 'em.

Solved! Thanks, Krileon.