Create account page

Hello,I noticed that after sign up, A create account page opens with two forms – account and profile details. Please would it be possible to remove the account details form? since one has already entered the required data at sign up. Users always react when they see the account details forms because it requires some data they previously entered. Secondly,Is it possible for someone to join a group at sign-up? that is, add a groups fields to the profile details form, such that once the individual selects a group he/she automatically joins a group.I mean, can someone join a group at sign-up stage? Thirdly, I noticed that at the end of the create account stage, an activate message follows, then once it is clicked from the individuals email, the site opens with the message- Account Activated- you can now log in with the username and password you provided… Question is, how can I bring the sign-in/ log-in button directly under this-Account activated message? Thanks