Questions about external vs internal HDD and media

[safetyobc]

I upgraded my stock 160GB HDD on my Macbook pro 2.2 about a year ago to a 320 GB thinking that would be plenty of space. Of course I was bad wrong. I have less than 10 GB left.

I have 2 options. Purchase a new 750 GB drive for internal. Or I can move my video media to the external drive (the old 160GB drive).

My question is if I use the external drive, will time machine back it up?

How would I tell iTunes to look at only the video from the external HDD and everything else internal? If that works then...

Can I access both the external drive and internal from my Apple TV 2 to watch the videos? I can currently access my computer and stream media to the Apple TV 2 and it works very well.


Any suggestions?

 

[Erasmus]

If you disable the checkbox in iTunes that mentions copying files to the iTunes Music Library, you can get iTunes to reference videos and music on external drives. Obviously you will only be able to use these files when the external drive is connected.

Also, a new internal drive will be faster than an external USB drive.