signing up issue

in my social theme.when the new user is signing up he goes here http://www.letstalk121.com/register-2/ now i dont want the profile to be filled by the used while signing. he can edit it later. also on the same page while creating his account i dont want the user name field.
also my query about members not able to signing as they do not receive activation mail is still not resolved which is holding back the site from going live.it is so frustrating