I use the browser only. If you don't need the email client, then don't download/install it. I've never used the Mozilla email client so I can't advise you on it. If you want, try it out and see if you like it. You can always uninstall it later.
When installing Mozilla, be sure to install the Javascript debugger. Mozilla also has a helpful DOM inspector at "Tools->Web Development->DOM Inspector".
Good luck (and thanks for the /art/star.gif).
-Ron
We all play from the same deck of cards, it's how we play the hand we are dealt which makes us who we are. -Me
murof siht edisni kcuts m'I - PLEH