Registration and custom messaging

so i've been asked to,
1) add a simple registration on a site
2) a functionality where administrators will be able to send some files to registered users
3) few pages which can be seen only by registered users
4) a profile page for each user with custom text in it

Which plugins should i use to accomplish that all the above?

I'm using the Novus Multipurpose Corporate Wordpress Theme from themeforest which has been deleted and as far as i know there it doesn't support buddypress.

Thanks in advance.