Recognizing Movies on External Drives?

I have a Mac and currently stream my movies (ripped by Handbrake) to ATV via iTunes. My movies are contained on two separate external 1TB Lacie drives that are daisy-chained to my Mac via firewire 800 cables. This setup works fantastic.

I successfully installed ATVFlash 3.5.2 yesterday and wanted to know:

  1. whether the only option for connecting multiple drives is via a powered hub (my external drives also have USB ports)?

  2. whether I could take my external drives, connect them to ATV and have them recognize the movies (all are MP4 format) automatically, or do I have to do additional steps?

  3. will I be able to use both my ATV HD and external drives simultaneously (currently the 160GB on my ATV sit unused)?

  4. I assume I can manage all of this via iTunes, which is what I prefer?

Thanks in advance.