It's 'Firefox' actually, not Foxfire!
Importing stuff just copies it into Firefox. What you import will still be left in place in Internet Explorer.
Be aware that, as good as Firefox is, some websites won't display properly (those that use Microsofts own version of HTML rather than the standard), and some plug-ins require a bit of manual work (Realplayer, Flash etc) whereas in IE the plugins set themselves up automatically. The biggest 'pull' Firefox has is having 'tabbed' browser pages, updates are more frequent than IE, and it's less prone to browser hijacking. The latter may well change as Firefox becomes more popular though.