The fourth generation iPod Touch has not been made yet, and there are several other iPods with a fourth generation, so specific information of the iPod is needed to know whether it can be jailbroken or not.
if you want it to be jailbroken then no,if not yes
you get about 110 at least but you can get more if its jailbroken
No. You will not see any performance difference.
if you mean the line then that is normal but if you have jailbroken it then that might be the cause
You have to go to jailbreakme.com from your ipod
Restoring an iPod should reinstate the warranty to a jailbroken iPod, unless a problem occurs during restoration, then the warranty isn't in effect since you are trying to restore a jailbroken iPod.
iPod 4G is better
The Jailbroken IPod has Cydia, which "unlocks" or makes your IPod capable of more tasks than a regular IPod.
Yes, you can put music on a jailbroken iPod Touch.
your iPod probably has a lock with a circle on the top bar next to the battery icon (if it is jailbroken or is an iPod 4g). If so, double click the home button and scroll to the music dock and press the button on the left. (screen rotation lock)
If someone you know has a iPod touch 4g, iPhone 4g and IPad 2
Yes, but it will erase everything on the iPod, including things available only to jailbroken iDevices, such as Cydia, Winterboard, etc. You can then put all NON-jailbroken media back on the iPod by using a backup file of the iPod which is saved on iTunes.