Use the form to get your user name/password.

It is impossible to change your user name/password, use the form to delete your old user name, then try to register new user name.

Only you and the site moderators can view your IP address and email. Regular users do not see that information.

This problem sometimes occurs with MSIE. Close all Internet Explorer windows and open Internet Options in the control panel. Click the Delete Cookies button. You should now be able to login.

You do not have to anymore. All you have to do is make sure you are logged in with your actual IP when starting a torrent session. After that, even if the IP changes mid-session, the seeding or leeching will continue and the statistics will update without any problem.

The tracker has determined that you are firewalled or NATed and cannot accept incoming connections.

This means that other peers in the swarm will be unable to connect to you, only you to them. Even worse, if two peers are both in this state they will not be able to connect at all. This has obviously a detrimental effect on the overall speed.

The way to solve the problem involves opening the ports used for incoming connections (the same range you defined in your client) on the firewall and/or configuring your NAT server to use a basic form of NAT for that range instead of NAPT (the actual process differs widely between different router models. Check your router documentation and/or support forum. You will also find lots of information on the subject at PortForward).