I don't know why you'd need to root in 2023. I'd stick to a secure custom OS instead that can have secure boot. Something like CalyxOS or GrapheneOS. Lineage or /e/ or something if you don't have a pixel.
I mean hey, anything's better the iOS lol. I don't think rooting is a good idea, but anyone running a custom aosp ROM is an ally of mine. We custom ROM users gotta stick together!
Sorry, I don't know the answer. I think it's highly unlikely since encryption makes the data unreadable but I imagine it be possible to decrypt the data from inside the phone, backup it and then re-encrypt it after restoration. Still not that sure tho so you can search the net and see if it's doable .
the trade between an encrypted storage and the ability of a full backup is a very bad deal. Unless you're talking for a phone that you leave at home at all times
For calyx and lineage: I don't think you can call the livedisplay settings CLI without root. For example I have a 1-click widget to turn my phones RGB values to all red. Or is there a way? (Needs to be RGB, not some crappy red overlay)
I have a degoogled phone without root lol, I'm running GrapheneOS. All you're doing is opening yourself to his security vulnerabilities with root. Desktops are entirely different then phones. Everything you mentioned does not require root.