There are many reasons for this.
You have to sync it because when you sync it go from your computer to your iPod but if you have an iPod touch you can download songs from your iPod's iTunes store.
Try unticking all the songs on Itunes. And add tick ONLY the songs you want to sync into your ipod. Itunes will only Sync the ticked songs. The rest of the songs on your ipod wont be erased.
This is probably because you have run out of room on your ipod.
No, it will sync every copy to your iPod exactly the same as in iTunes Library
You cannot change the order of songs on an iPod, only on iTunes.
The easy way to do what you want to do is to make a file called Christmas songs and list the songs in that file. It will stay on your IPod, but you just don't listen to them. You could also go in Itunes and uncheck the songs in your library that are Christmas songs. Do a sync of your library to your IPod and the songs will stay in the library, but not be on the IPod. When you want them back go in to Itunes and check them, sync, and they will be back on your IPod. If you want only Christmas songs you would check all the songs that are not Christmas and sync. Either way the songs stay in your Itunes library, but are not on the IPod.
You plug your iPod into your Mac using the sync cable and sync songs to your iPod through iTunes.
delete them from your itunes libaray then update your ipod.
Either: -Remove the songs from your iTunes library or -Create a playlist and put all of your songs into that one playlist. Then change your iPod settings to not sync all music in your library, but instead only sync selected playlists. You can then delete songs from the playlist but still have them in your iTunes library, and they will therefore not be synced to your iPod
Either: -Remove the songs from your iTunes library or -Create a playlist and put all of your songs into that one playlist. Then change your iPod settings to not sync all music in your library, but instead only sync selected playlists. You can then delete songs from the playlist but still have them in your iTunes library, and they will therefore not be synced to your iPod
you can burn the songs you want to sync onto a CD and then download them to your iPod from the harddrive
if you plug your iPod into your computer it will sync your music to your iPod. Or you can buy your songs with the iTunes app on your iPod touch.