Login/Register validation and return errors

Seems like the login/register extra expects us to show all our error messages inline with the form fields. I need to show ALL validation errors at the top of a [very long] registration form, including a couple of custom validators. So;

1. isn't there some way/placeholder/method to just dump all the errors?

2. is there a way to pass the name of a form field with the ":required" validation so that the errors don't all come back as "This field is required"? [i.e. maybe something like "username:required:`User name`" = "User name field is required" ]

-thanks