Depends on the size of the iPod, the size of the videos you want to put on and the total size of the 425 songs on the iPod
No.
NO otherwise it will delete the songs you already have on there!
You have to have iTunes.... When you got the iPod it shouldve come with an itunes app already in it..... look up the song you want then click buy song... just make sure you have money on your ipod....
If you already have the songs on your computer you just simply need to sync your ipod touch with your computer.
This ipod manage software can transfer the files from ipod to computer, ipod to iTunes, and iPod to iPod: http://www.ipodtransfer.net/how-to-transfer-ipod-file-with-ipod-transfer-software.html
There is a way of adding a folder to your ipod and then compressing all your songs and putting them into this folder. The folder should be put on to the ipod in the ipod settings with the other folders like music and photos and such. If you look on the mac website someone will have probably gone into more detail.
See links to Apple.com
You Can't But You can put the songs on your ipod onto itunes then put them delete them And then sync ipod with itunes. then you will get them back and you will get then new ones to. i hope that answers your question.
Anything you have on your computer, just use the conversion software that came with your ipod.
Yes you do have to pay for music on your iPod touch. Some songs are $0.69 to $1.29 but they can also be $0.99. You can buy them from your computer or from your iTunes app on the iPod. You can also put music that you already have onto iTunes and then transfer it to your iPod.
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.