1. Regarding Memory Maker - the last time we were at WDW (4 years ago) we had a plastic card for the Photopass photographer and he scanned it and voila our pictures were zapped into our account - do they now have to scan our Magic Bands to link up our pictures or are the pictures just zapped there without having to scan the Magic Bands just because we're standing so close to the photographer?
You can use whatever your tickets are with. If you have a magicband, that's all you need. If you have a hard ticket you use that. If for some reason you don't have either or something happened with them while at the park you can get a photopass card from the photographers but that's really rare these days...
Something to note, ride photos now automatically link to your account if you have a magicband with you (wearing or in your bag/on your person if you are concerned it may come off on some rides). (and the magic band batteries are still good). Some rides (not all) still have the screens, you do not need to review and tap your band for them but you can if it makes you feel better and ensure a picture of you was taken. some rides don't have them and you must have a magic band to get those photos. Also some rides have video of you riding it and that also requires a magicband.
Also some rides have a new storyteller option, which means part of the ride is peronallized or someone may greet you by name. these require a magicband also so they can detect who you are.
Batteries last about 2 years if you travel to disney a lot and keep reusing the same magicband. Room key, tickets, dining plan, anything you touch your band too work even if the battery is dead, the batter is just the features where it wirelessly tells the system where it works and that is limited to ride photos, videos. The only way to tell if the batteries are dead is to ride something and see if storyteller or a ride photo appears automatically. *Yes it's annoying, especially if it was a long wait*. you can ask for them to manually link your photo if you discover this happens so you don't need to ride again.
2. We have dinner at HDDR - the last time we ate there was 7 years ago and we had to pick up physical tickets at the box office just before our dinner time - are those zapped into our Magic Bands too or do we still need to pick up physical tickets at our hotel?
If your not being told to pick it up or it is being mailed to you, there is nothing to worry about and your magicband is all you need. It's rare but there are some special circumstances where a hard ticket is needed and it will be very clear you have to do something extra when you book. Again, no information means magicband is good to go and don't worry or be anxious.
The exception to this is early morning before park opens tours where you have to meet in the park. These cannot be linked, there is no ticket and it's a person with a sheet saying who to let into the park early at the entrance. If you do any tours like this, the disney site does have a spot you can add notes to your plans with times so you can remember it's there and add your confirmation number so you don't need to carry anything extra around.
are those zapped into our Magic Bands too
This is where the bands are confusing, nothing is zapped or linked to your band. Everything is in your disney account (
MDE) including your bands. Any bands you have work interchangeably. The disney system just uses your band to know who you are so the computer can look up what tickets, dining, fastpasses, etc you have. Same with room charging, it uses the band to know who you are, you type in a pin code at time of purchase to confirm it's you and your done. It's really made a lot of the system streamlined and linked together instead of like the old days where you carried a dozen cards and had to use a different one for each thing.