Ok, as I understand you, you have somethings in Netscape that you wouldn't like to erase/mess up, right?
You can download the latest netscape installer from home.netscape.com
, make sure it is the stand alone one. Now do not fear it is a tar.gz file, cause it actually contains the binaries necessary to install. Untar, install and surf away. Now if you have Java working, just download the latest java plugin for netscape 6 (it works on NS 7). It also comes with Flash player 5. If you have any mail/newsgroups/bookmarks from your original communicator, you can simply copy them to your /home/$USER/.nsmail directory to catch 'em up. Good luck upgrading. And remember, once everything is working you can uninstall (rpm -e netscape-communicator netscape-common plugger) your old installation.