User Configuration

Can I create a second username for my account?
Can I create a second username for the second holder on my Joint account?
Can I create a username for a third person on a Joint account?
Can I change my primary username?
Can I change the account holder of an individual account?
How can I create an account alias?
How can I configure my user settings?
How do I modify user access rights?
How can I configure my trading platform settings?
Can I use my email address as my username?
Does adding a user impact the tax status of my account?