That’s what iCloud is for. Why the need for all the complicated solutions? iCloud is a synchronization service. It’s main purpose is to sync all your data, including photos, across all your devices.

As for photos, it does not alter (compress) the photos. The original, hi-res, images are stored in iCloud and can be downloaded to any device. The default setting is to store lower resolution versions on device to save storage space but as soon as you go to view them the higher res version is downloaded on demand. You can also choose to change the setting to always have the original hi-res version on devices as well with the caveat being that they will take up more space.

You don’t have to lose access to Apple Music or the previously purchased apps. All you need to do is create a Family Sharing group. All members of a Family Sharing group can share purchases and things like Apple Music subscriptions and you don’t lose any privacy since each Apple ID is separate.

Everyone in the family should have there own Apple ID and they should be joined together as a Family Sharing group to share purchases and subscriptions to thing like Apple Music.

https://www.apple.com/family-sharing/

Correct, Quick Start does not use iCloud backup. The whole point of Quick Start is to transfer the data directly from one phone to the other.

Anyway, as for the Apple ID, just log out of the shared Apple ID before starting Quick Start and once the new iPhone is set up just log in to your new Apple ID.

Now since you are getting your own separate Apple ID you will have to get all the apps all over again including purchasing any that were previously purchased since apps aren’t transferred during Quick Start set up.

Okay, how about all the other iCloud services, have you turned them off? If you go to iCloud settings you will see a list of services like Photos, Calendars, Contacts, Notes, etc. Have you turned all those features off as well?

Need some clarification. When you say ‘shared Apple ID’ are you saying this Apple ID is used by other people in the family or that it is part of a Family Sharing plan where everyone has their own Apple ID?

Also, are you logged into the Apple ID or not? You say you never turned it on. What does that mean exactly?

When you re-enable iCloud for the contacts it should recognize existing contacts and not duplicate them. If any data was added or removed while iCloud was disabled then a best effort will be made to merge the data.

Contacts stored on iCloud are always also stored on device. In this scenario, like with most of iCloud’s services, iCloud acts as a synchronization service so that the data stored on one device is available on all devices.

Okay, just so you know. When Contacts is configured that way it means the your contact list is available only on the iPhone. That is fine if you never have any other devices like an iPad or a computer like a Mac. If you have more devices and you want your contact list to be available on all of them then you will want to move your contacts on to a list that is available on iCloud.

That is the purpose of iCloud. It is there to synchronize information on one device to iCloud so all devices can access the same information.

On the top-left of the screen does it say ‘Lists?’ If yes, tap on that and on the next screen tap on ‘On My iPhone’ if it is available.

https://imazing.com

If your mother is setting DND or any other focus mode that is blocking your ability to contact her you should first delete all the focus modes. DND can’t be deleted, but you can set it up so that even if she accidentally enables it you are allowed to get through.

As for other settings you could try and see if ‘Screen Time’ can be used to create some restrictions. Also you may consider deleting apps, even default Apple apps, that your mom doesn’t need to simplify things for her.

No.

No one really knows the answer to that. We’ll have to wait until some actual announcements start to be released about devices that support it or are being updated, if any, to support it.