A. At any point that anyone in the group goes to get a photo taken by themselves, they can simply as the Photopass Photographer for a card.
B. You can link the cards to your mothers Photopass account at any time, even after you get home. The photos will be connected to the card, and then the card can be connected to the account.
C. SOME of the rides have a set of screens / touch points after the ride, where you can claim your photo. Other rides do not, and I am not aware of any way to claim those photos without having a Magic Band.
D. The rides take photos of everyone. The only reason for the band is so that the system can identify you and connect your photo to your account. Likewise, as I stated above, that can also be done manually at touch points after some of the rides (Buzz Lightyear comes to mind as one where you can claim your photo after the ride)
E. That is a great question. I know that you can have photos taken at the resort via the Fine Art Photography for an additional charge. I don't believe I have ever seen a Photopass photographer at a resort aside from some of the meals where your photo is taken as part of the package (Chef Mickey's for example)
https://disneyworld.disney.go.com/guest-services/fine-art-photography-video/