are you kidding?? users have been able to donate to each other since 1.0
whenever there is a user's account amount somewhere, it should have a donate link near it.
in regards to the unregistered/logged in missing vbcredits settings - that is intentional. why would guests have any access to vbcredits? they cant have accounts... so cant earn or spend..
also, vbcredits.com appears to be fully restored now

so all the links work