You will not have to pay again.
No
You should download iTunes. If it does not work download it again. Make sure you have your ipod up to date and you have the new version of iTunes.
no. everything from your iPod will be erased, but your itunes will stay the same, so when you sync it again, everything will be on your iPod again
If this happens, then the time when you will sync your iPod to iTunes, all your songs on your iPod will be deleted. If you want to prevent this from happening, connect your iPod to your Mac or PC, iTunes will open with a warning message, just refuse to format your iPod, then download a software called 'Touch Copy'. There is a free trial version I think. Follow the steps, and all your iPod contents will be uploaded to your mac or pc. Just add everything to iTunes again and sync safely. Thanks.
You only need to download itunes again is if you deleted it, got a new computer, or are needing to upgrade it to the new 10.01.0
You cannot use an iTunes gift card twice, for once it is used the servers at Apple will know that it has already been used, therefore you cannot use it twice.
No.
Itunes has it
Yes you can, simply go to the iTunes store and download them again, of you purchased them from iTunes.
If the song is permanently deleted from every source you have, you will just have to pay for it again.
Put on a song as you originally would have from iTunes. If you never downloaded it from iTunes, but rather directly onto your iPod Touch, then just buy it again. iTunes should recognize that you already bought it, and will ask you if you want to download it again for free.
it should be in your itunes librery