We've used this twice now. Anyone on your friends and family list can add pics to the account with their magic band. I'm the primary person assigned but my mother and sister in law were able to add expedition Everest and dinosaur photos.
Also Once I compiled the photos for download anyone is able to download them as long as you've given them "permission" in your account.
I'm pretty sure anyone can download at any time but once you start the first download that begins the 30 days on your account to collect photos. It's weird. Cause I purchased it back in February and have been adding photos from two different trips. I just downloaded them for the first time the other day and it said my 30 days to take pics and add them would start from that day.