7 Dwarfs ride photo and video are definitely only available to people with a MB. I had mostly on-siters and a few off-siters on my last trip and those without a MB (off siter who didn't choose to purchase one) did not get 7 dwarfs photos. THere's no way to capture you without it, no preview screen at the end where you would get your photo number. We did not purchase attractions+ because we had full memory maker, so I'm not 100% sure, but I believe the 7 dwarfs photo would be included in attractions+. I think the only reason it's not on the above list is because the available online info is dated 2013ish and the ride didn't exist then. Otherwise, all rides with photos are included on the list, so I believe 7 dwarfs would be part of it too.
I can't tell for sure if the 3 days thing is cleared up: If you buy online at the discounted price, there is a 3 day wait before your pictures will be included in MM (although I believe if you're there, you would still see those pictures and you'd have to pay separately for those downloads) If you buy at full price on arrival, it is active immediately.
Attractions+ is definitely only good for ride photos. No character meets, meals, or dinner shows are included in the price.