I think you are complicating things too early in the process ...

You are shooting DV interlace. You have to be, that is all your camcorder can do. 480i
If you (or your subject) does a simple file transfer from tape to a hard disc, you will have a DV.mov file assuming you use a straightforward method, without conversion or reformatting or recompressing. I advise you to do that. You will then have a DV file that takes up 1 gigabyte of space for every five minutes of material. It will be 480i, and will be EXACTLY the same as what you shot. You can copy this, edit this, transfer back to tape, copy to a hard drive -- you will still have your original 480i file exactly as shot, no loss of quality.

Note that I have avoided talking about tools -- everything above is tool agnostic. You can use Quicktime, or Final Cut, or Premiere, work with a Mac or a PC -- the file will still be exactly the same. I see nothing but trouble in converting this file at such an early stage to anything. You didn't shoot 480p, don't convert it to 480p until you are finished editing and exporting for delivery. You didn't shoot HD, don't convert it to HD until you are finished and exporting ... see what I mean?

Open a standard FCP DV project file. Edit your project using the 480i source files. Export to what ever you feel is best for delivery -- now is the time to convert to 480p if that is the route you choose, h.264 if you want, et cetera.

I still have a PD150 kicking around that I use to shoot quick interviews, record direct to hard disc, edit the DV files & export as h.264 files to include in a web site. Shoot in the morning, edit, export & post the site in the afternoon. Could do the whole thing in a couple of hours if I didn't factor in drive time & lunch!

Cheers,
GB

Thanks Geoff. If you or anyone else is interested in what the problem/solution really looks like. I've posted screen shots of all the conversion methods in my public album in my public profile.
Thanks again!
Scott