No you will need to restore your Apple device.
Yes, first sync your ipod though. Don't update to 4.3.4 or 4.3.5 yet as those have no untethered jailbreak.
what do you mean once it jailbroke... ...it jailbroke unless you tern it off or it runs out of battery then you will have to re-jailbreak or if you uninstall the program
You do not Jailbreak iTunes; you jailbreak iPods and iPhones.
On most tablets you can't uninstall the preinstalled app. However, if you look into rooting your device there are some options. Other options include installing a new ROM (a new operating system) which is a bit advanced but can allow you to make your tablet more custom (if it's an android tablet). If its an iPad there are apps to hide the preinstalled apps, but you'll have to jailbreak it to uninstall.
If you mean on an IMac, all you need to do is move it to trash and empty the trash. It deletes all the files with it (Unlike windows). If you mean an IPhone, then I am pretty sure it is not possible unless you jailbreak.
You jailbreak the firmware.
Yes you can. there is a new jailbreak out called "spirit". Google it "spirit jailbreak"
Updating the iPod Touch software erases the jailbreak. You can update, but it will erase your jailbreak.
No. Your jailbreak will remain as it is. Syncing your iPod does not alter the jailbreak in any way.
uninstall shield is just the name of the program that uninstalls it.
Do what you originally did to jailbreak it in the first place.
Can you jailbreak a coby kyros