After adding AnonymoX, my browsing slowed down considerably. I would like to uninstall it but cannot find a location or tool to allow me to get rid of this add on.
If you go to "Tools" - "Add-Ons" and then click on "Extensions", can you find it there? I just tried to install it and it appears in that extensions list, I can remove it from there.
Check the connection settings.
If you do not need to use a proxy to connect to internet then try to select "No Proxy" if the "Use the system proxy settings" setting or one of the others doesn't work properly.
See "Firefox connection settings":