Good to hear, mouser, thanks. To be honest, knowing myself, I don't think I'll ever have the problem of accidentally erasing or formatting large quantities of files. But I wouldn't mind being able to somehow "lock" the drive except for the times when I backup. No big deal though, I'm not too worried.
As far as swapping, I'm going to use SATA drives, so I've learned that you can just hot swap them, which is cool!
You know, if there is any interest, I may write a short article of the details of my backup solution once I finish everything. It's nothing fancy, but there might be some people who would like to read it. I'll include pictures also. I know I've started 2 or 3 threads that are related to my quest for the perfect backup solution.