How can I let non-registered users ask/answer questions on Q&A

Hello there – I’m looking to use Q&A to allow non-registered users to ask/answer questions. Is this possible? If so, how?

One nice twist would be is if they had to be subscribed to our mailing list (held with MailChimp) in order to ask/answer. Again, is this possible?

C’mon WPMU you’ve not let me down yet…

(FYI it’s for not but I’ve not installed it on Staggered yet.)