One last question...again. I just did the HTC EVO hacks to unlock bootloader. So I am S-ON with unlocked bootloader. Am I able to nandroid even with S-ON?
Yes you can but you will need to install a recovery first. I recommend TWRP no root required
Root is for the operating system, it allows access to your system files so you can make changes to them. which if you install a custom rom it will have root included