I was given avi files to import into Final Cut Pro 7 for editing. This works fine. I can view them and edit them.

The avi files are:
Vid Rate: 29.97 fps
Frame Size: 720x480
Compressor: DV/DVCPRO - NTSC
Data Rate: 3.6 MB/sec
Pixel Aspect: NTSC - CCIR 601

The DV was shot in Standard Def, 24P Advanced, 16:9.
Should I convert the files back to 24P Advanced before editing? If so, why?

Are avi files a compressed or lower quality video than the 24P directly from the DV Camera? (i.e. Should I capture directly from the camera?)
If I edit with the avi video, can the exported video be used to produce a standard def 16:9 DVD? (i.e. Is 720x480 dvd resolution?)