Display / edit Domain, and other suggestions

[KNBu5ZMdbR]

I made a mistake and entered a computer name, instead of a domain, while completing the e-mail portion of the certification test.  I entered something like:
        johnDoe@foo.bar.com, instead of   johnDoe@bar.com.

Foo.bar.com is my mail server and I passed the test, but I think I was stuck with HE thinking that my domain is foo.bar.com for the remainder of the certification.  (I've since sent an e-mail to ipv6@he.net asking that this be corrected).

Some suggestions:

1) Check that an MX record exists for the domain;
2) Display the domain in the test web pages -- Subsequent levels highly depend on this domain value, and since I'm doing this in my spare time, it's easy to forget or become uncertain about what you think my domain is.
3) Allow me to edit the domain.

Also:

4) I'd like to repeat the tests.  After learning more of IPv6, because of the tests, I'm improving my system and re-certification seems like a good regression check.

5) On the multiple choice tests, the text says something like "You only answered 20 of 21".  That's wrong.  I answered them all, but only 20 were correct.

6) The radio buttons are very hard to use.  Maybe it's fat fingers, but it seems like some certification test gremlin is altering one answer or another at random.  Even though I know the answers, it's hard to click twenty+ radio buttons and keep them straight.  This is why (5) bugs me.

It'd be more coding for you, but perhaps on my 2nd try, give me my radio buttons back, pre-selected to whatever I submitted.  Then I can just concentrate on the wrong answers and easily resubmit the correct ones.

Thank you for providing the certification tests.