You can move the facebook, or other variables, elsewhere. All you have to do is preregister the variable for use in the new template. Cellarius wrote a really good article that you may be interested in -
[vB4] Rendering templates and registering variables - a short guide
I very much doubt you want to be modifying GENERIC_SHELL, because, well, it's generic and just not used on most any page you will be looking at. To find the template to modify, do this - vboptions > General Settings > Add Template Name in HTML Comments > set to Yes . Then go back to your page and view the source code and you will see the name of the template called around your part of the code. (Sometimes the template is the one mentioned at the very top of the page source.)