Yes, the photographer will need to scan your band. If you link the Memory Maker to the rest of your family, it doesn't matter which band they scan. Good idea as probably the kids will like getting their bands scanned and also in case you split up.
Tips? Ask for Magic Shots and just stop when you see one. If you are on Main Street or in front of the Tree of Life, there are usually more than 1 photographers, look if there is one available right away. It can get out of hand ;-) We returned from a 10 day trip with about 800 - 900 pics.
I would advise to check the pictures in the evening on your laptop/phone etc. if you have the option, or check with the photopass service centers in the parks (and I think most hotels). If some pictures get messed up or are missing, they are the ones who can do something about it.
On Day 4 of our visit, we visted Merida, first thing in the morning. Due to the humidity and the photographer coming out of the air conditioned back stage area, the lens kept fogging. Our first pictures look like we stand in the mist. On day 7 we are in MK again and go by Guest Relations to see if there is any way we can re-do the pictures without having to get in line again. Merida's lines still get long. The CM apparently never heard this question, kept saying 'I don't think so, she has no FP option' first, then changing it to 'I don't know', so I ask: Can you check? In the end, no it wasn't possible.
On our very last day, we decided to get in line again, first thing in the morning to re-do the pictures. Humidity wasn't as bad anymore, so fingers crossed.
On our way out, back to the hotel and the DME, we go by the Photopass service. We explain why we want to check. The CM there, Lauren, tells us that we were misinformed. If we had come to her, she would have taken us right away to Merida to have our pictures re-taken.
So... long story short: if you have a question about Photopass while being in the park, don't go to Guest Relations, go to Photopass.