further update: in trying to figure out why the icons were now working in Firefox and Safari but not in Chrome, I found that the font files are actually included in the theme files but they do not need to be (unless there’s something I missed). In fact, their inclusion in the theme leads to trouble if your site files are installed somewhere other than the url of the site itself.
If you don’t have access to (or don’t know how to use) the .htaccess file, the solution is simple. You must add
<link rel="stylesheet" href="//maxcdn.bootstrapcdn.com/font-awesome/4.3.0/css/font-awesome.min.css">
to the header.php file after the <head> statement. You can find this file by going to Appearance > Editor and then scrolling down to Header in the list on the right. After clicking on Header, look down a little bit in the file and add that statement after <head> and you should be ok. I’ve since returned my .htaccess file to its initial state and all seems fine.