Yep. What Sean said. It works a treat, although the download limit of 15 pics may be enforced that way (I'm sure Gus will confirm).
Yes but you need to add .ning.com. So it'd be firstname.lastname@example.org,
You can find it at the bottom of your settings page here.
If you use the mobile version of the site you also need to change the email address it defaults to with ning.com (if you can, I'm not sure). And it is generally limited to 15 pics per person per day.