So that we can all enjoy fun, fair games we need to quickly double check that you're a human and that you have an e-mail address. It only takes a moment and it keeps the server free of spam and cheaters! :-)
You may only have one account, second accounts are not allowed under any circumstances, and will be banned. This may also lead to your first account also being banned.
You can't make alliances for reasons outside a game, such as because you are friends, relatives or in return for a favour in another game. This is known as metagaming and is against the rules because it gives an unfair advantage to those involved. If you are worried that you can't stab someone because you want to stay friends, then that's fair enough but you can't join a game with them.