Would a full back up (from recovery) preserve all data including installed apps? I wonder if I create a full back up from recovery, would it preserve all my data? Including installed apps (along with their configs) and my contacts?
If you are talking about a Nandroid backup: Yes, it would. It creates images from the devices file systems -- so all that's stored there gets copied to those image files. You can then even extract single items using e.g. Titanium Backup.