I can answer that. You can DEFINITELY downgrade to a smaller package (or individual photos, or cancel) any time before Debarkation day. They may not want to talk about it, but you can do it, no penalty. One thing to note is that on some ships they aren't doing prints anymore apparently, everything is digital. So I don't know if you were talking about just getting a few prints or a few digital copies. The digital copies come with full rights so you can have any company print them out once you get home.
I'm not sure how you ended up with only 8 pictures LOL. We got Goofy in the Terminal, the Sail Away picture as we boarded (a bit of a line there), The formal night pictures (three locations: stairs are the best, but line is the longest), pictures at dinner 3 or 4 nights (you can ask to stand away from the table if you don't want dinner plates in the pictures; I loved the different pairings they got at dinner, so make sure not to always sit in the same order), the picture with the ship when you get off at CC, pictures in the water at CC, the 2 Sets of Meet and Greet Photos (Frozen and each of the 4 Princesses), and several with individual characters at other times. So in all we got like 90 pics in 7 days.
I will confess that I am fortunate that my sons are "Drama kids" meaning that they are in the school plays and thus have no issues being in front of a camera or being "silly." They got into "hanging out" with the characters, becoming part of the fantasy.
One last thing, between the whole family we took about 4000 pictures during the week, and of the 40+ pics that I chose to display at my desk at work, 40% of them are from the picture package. That to me, means it was worth it.