Questions about "Nandroid" backups
Good Thing you don t have a Samsung (KNOX wont let you easily downgrade).

To answer you questions to a certain extent:


depending on how you did your nandroid backup 
it won't be "precisely" the same (e.g. most users dont backup the Cache).
no, but maybe you don't want the "EZ-backup and Restore" procedure - Sounds to me like you would like a "dual boot" maybe? If so see this thread:
http://forum.xda-developers.com/nexus-4/orig-development/mod-multirom-v24-t2472295
define "visualized", you could copy the backup to pc and see the backup files. is that what you mean?