I pretty much know how to get everything back in place without using any backup except for iMessages/SMSs. Is there an easy way to do this?
This should be doable, using an iTunes backup of the phone. Obviously you should create a new backup immediately prior to doing a fresh install. I haven't tried this, but I've been thinking about it myself as I ponder whether to jump to iOS 7 (probably not, as I don't have a dedicated test device, and the iOS 7 Simulator should be sufficient for testing my app for now).
In your mobile device backups folder (
~/Library/Application Support/MobileSync/Backup) there will be various subfolders for the backups you've done. Inside the latest backup folder, the SMS database should be named "
3d0d7e5fb2ce288813306e4d4636395e047a3d28".
I'm not completely sure if this would work since I haven't experimented with it, but this is what I'd try. I'd make a copy of that latest backup folder, rename it with the current date/time, and then delete everything inside
except for the SMS database. Hopefully iTunes will then see it as a backup containing only that one database, and you'll be able to restore as if it were a full backup.
Of course, it may not be quite that simple, depending on how finicky iTunes is about the MobileSync/Backup folder. Good luck if you try it.
Edit: see also
http://senseiphone.com/iphone-backup-location-files-05203655/