Yes. Just click "buy" and drag the song over to your playlist.
yes
Yes. It is very possible to have 7,000 songs on an iTunes account.
Yes
You can download music without losing songs. Unless your iPod doesn't have any more room for music. You can download songs from iTunes. You can buy songs form the Apple store or you can download songs from a CD. You can put music on your ipod by dragging the song(s) to the little iPod logo, located on the right hand side of the iTunes menu.
yes, if you had those songs on your itunes they should still be there when you log onto your itunes account
You can buy an ipod or create an account on itunes so you have a "library" of music to listen to.
You don't have to upgrade iTunes, you just can set your ipod touch to a "replacement" even though it's not.
You need to delete it from your Itunes account.
Sync them with your computer to the same iTunes account. The songs will be downloaded automatically. Songs made with the programs such as Garageband can be shared via iTunes as well.
No, however you may pay for songs off off itunes but to get itunes it is 100% free
Cash can be used to purchase an iTunes gift card which are available from many retailers. You can then add the value of your gift card to your iTunes account to buy songs from iTunes.
You can move your iTunes music library from a Windows computer to a Mac without losing any of your songs. (See links below)