You can't. Apple strictly made it so that if anything were upgraded or restored then the iPod would have to resync to have the songs, pictures and apps that you had on it put back on the iPod. What it does is it will tell you that the memory will be wiped clean of everything no matter what you do so if you don't have all of you music apps and pics anywhere else then you're basically screwed. I had it happen to me. My computer crashed so I lost everything on it and when I wanted to put more music on it the iPod said it would have to overwrite what I had on it already so I'd be starting all over. Do yourself a favor and every chance you get just sync it and have everything backed up. With out apple backing it up online you won't have anything you had before. Hope this helps.
once restored, everything is gone!
when you restore an ipod it doesn't delete your songs or apps but it will delete your high scores from the last time you sync your ipod.
After doing the full restore, you cannot get your jailbroken apps back. This time, you must actually pay for the apps.
for sure the apple id is important only to buy stuff and download apps
No it will restore the apps automactically
No. If you sync your iPod it wont delete your apps. But if you click "Restore" while the iPod is plugged in, then it will restore you iPod to how it was when you bought it (no apps, no contacts, etc.) and then update it to the newest version of software.
Yes, it does
Yes, you will.
Those installed after the date of the restore point used will be removed.
If it does not have ton of apps and or songs, It should last about a day or half a day . If it does have apps and songs it would last about 3 or 4 hours .
Restore the Ipod
No. You restor it to the original software.