No you can't, sorry :(
No you can't add space well you can but it would void and mess up your warranty
No, you cannot add a camera to the iPod Touch, be it an external or internal camera. The iPod Touch does not have the capabilities to do so yet.
To add apps to the iPod Touch, you can either download them from the App Store via Wi-Fi on your iPod Touch, or you can sync your iPod Touch with iTunes through your computer.
You must have itunes installed on your computer to add music to your iPod Touch.
You buy the song and it pops up on your ipod touch!
Yes, but you must add people they can not add you.
I think it all depends on the model of your iPod. But I can give you a website, you can have a look and find out whether there is a SD card suitable for your iPod. http://www.dinodirect.com/iPod-Accessories/
For the iPod Touch 4: If the ipod touch's owner has the iphone owner's number, they can add it to 'contacts' and press 'facetime' and it should work. If the iphone owner has the ipod touch owner's email address, they can add it into 'contacts' and press 'facetime' and it should work.
Yes, you can.
You cannot add space to an iPod Touch hard drive, or any other iPod hard drive. The hard drive capacity is set and cannot be changed.
Adding Themes is only available to Jail broken, iPod Touch, and iPhone users.