You rename the .m4a file extension to .m4r and the iPhone will use it as a ringtone
Question: Will it restore the ringtones you set for your contacts? About the only backup solution that comes close to iOS through iTunes or iCloud is to use TitaniumBackup and the only way to get that functioning properly (last I used it) is to root your phone. Changing icons and the names of icons is purely cosmetic... getting hacky with that compared to backing up your device..just not even in the same league to draw a comparison.
iTunes stores backups locally.....
Edit: Oh wait, Nandroid is the "image" backup, right? Do you have that setup to run everyday or do you have to actively make a backup? Does it require root access to do any meaningful backup task? My backup happens every night over wifi when i plug my phone into my charger.
I don't have to change any extension to make a sound file play. That might just be a Samsung thing though as I haven't used other Androids nearly as much as my Captivate or my GS 4.
Yes, Nandroid is an image. I can install other ROMs and swap between them without the use of a computer. I backup the image to my computer just in case.
I have an older version of TWRP (custom recovery, kind of like a BIOS) so I have to backup manually. I'm not sure if the newer versions do this.
Sometimes you need root to do this but that depends on the phone. Normally on phones with an unlocked bootloader you load the recovery before root. At least that's been my experience.