User Referral site, what is the BEST way to setup this website?

Hi there,
Final goal is to build a affiliate/referral website (without the affiliate module, which is totally a different thing..)
I got an IDEA of creating a user referral website, which will work this way:

1) Upon registration, each user gets his own subdomain (subdomain module can help here)

2) When new user (anonymous) visit ANY subdomain (eg: Jhon.example.com) he reaches that exact same content (meaning - all users share the SAME content) - thought of just using block visibility option and set it to user/*

3) On each and every user page there will be a registration form, upon filling up this form, the user which OWN the profile gets a REFERRAL point (using Referral Module).

I thought of using setup OG automatically for each new user (though don't know how to do that..)