your question makes no sense waht so ever !
learn your grammar
If you want free things on your iPod, you have to jail break it.
The ipod touch is way better, u can do more things on it.
No, there is presently not an app for the ipod touch to weigh things on its screen.
no it is not only if you want cool things on your ipod
the itouch has more and better things then the ipod nano trust me i have both
The iPod Touch should not delete things when you update it. All content should remain on the iPod (unless you have a jailbroken iPod, in which case it will remove all non-App Store apps and other jailbroken features).
Yes
ITunes
lots of things
you can jailbreak it which means to hack the ipod to get games and other things for free. but beware it breaks the ipod over time
no it will not delete it by itself but to download things that are new onto tour iPod then you are going to have to delete it or start downloading things on your iPod with your old computer again.
its for if you damage your ipod and have the warranty to get a new one you back it up on itunes and it saves all of your things from your ipod to your itunes so you can just download it to your new ipod people usually do that if their ipod got cracked, dropped, etc or you could do it just to be safe so that if your ipod does get fully broken they can have their things on their new one if they get a new one.