Questions about Ex HD's and backing up

I'm going to be getting an external Hard drive for my Macbook Pro. I was thinking 1TB but now leaning towards two 500GB, so that I could use one for backup. Few questions:

1) Can I back up things from my computer and external HD#1 -> to external HD#2 easily? I know that time machine allows easy back up from computer to external. But is it as simple when going from external to external? Is this a different setup?

2) The hard drive I'm using to store all my backup files, can I still use it for other things? I'm not gonna back up everything that I have, just 200 or so gigs. Or is it better to leave your backup hard drive alone and not use it?

3) Can you recommend any hard drive for video editing? I'm going to school for video production so need one that will be fast when running w/ Final Cut Pro and not drop frames or anything both on the capturing and accessing the files later.

Thanks

It all depends on what backup method you plan to use. If you use Carbon Copy Cloner or SuperDuper or the like to clone your entire drive, the answer is no. You would need to partition the drive to one partition for your backup and one for your other files. I haven't used Time Machine, so I'll defer to someone else on that one.

The way I did mine is to partition the external so that one partition was equal to (or actually slightly bigger than) my internal. I called that partition "Clone". The remainder of the external was called "Media" and I used it for holding my photos and iTunes and anything else I did not want on my internal. I used SuperDuper to clone. I also have another external that I back up to and keep out of my house (offsite backup is always a good thing). I partitioned it in the same way, just changed the names of the partitions enough so that when both were mounted, I knew which was which. SuperDuper had no problem copying the "Media" from the one drive to the "Media2" on the other external. Worked like a charm.