Customers and prepopulating fields in checkout

My site has 10,000 members but after installing Eshop i have 0 customers.

I understand that there are no customers because they haven't bought anything yet, but is there a possibility for me to import/sync members to be customers?

At the moment when i am logged in and go to checkout none of the fields are prepopulated with any of my user data (eg name, username, email etc).

This should happen

I also have jomsocial where members can fill out fields like Address, City, Country etc. Would be good to be able to map those jomsocial fields to eshop so that it saves the customer retyping it all again and then makes it a quicker checkout experience

I have a similar issue - I would like to offer a member discount to registered users of the site.
We use CB Subs to sign up members. To be able to reuse their address etc. would be clever.

Is this possible?