Phone number: it's optional. I told a standard sign-up forum-you only need email. There is no required username, but I can add that. The TOS you should see on the bottom once you sign it, i can change to anyone able to see
I tried it just now and I saw that the phone number is optional. But see how the phone number field looks like:
This will not let people know that it is optional. It would be better if you can added optional somewhere around there.
Also you did not answer my second question. I registered. No username was requested for while registering but I was asked tmfir user name when j want to login. What is the username? I used my email but it did not work.