Running this page through the w3c markup validation service
found 66 errors and 7 warnings, and the page does not validate as xhtml strict. Before worrying about rendering properly in all browsers, you should start making sure your page actually validates as what your doctype says it is
. Once you're sure it validates with no errors or warnings, you will probably find there aren't many (if any at all) exceptions you have to make for browser compat amongst modern browsers.