Alexander, thank you for the detailed and very helpful post. I tried a NTSC to PAL (simple DV PAL setting) conversion and it produced results that I was unable to fault.
I was initially experiencing render issues in FCP sequence timeline, I mistakenly though it was sufficient to change the PAL or NTSC settings in the FCP/ video and audio settings, then I changed the FCP/sequence/settings from the top toolbar and that appears to have fixed the need to render clips in sequence timeline.
I suppose it doesnt make any difference if I edit the clips in original NTSC or convert to PAL then edit?
Again thanks for valuable advice.
Chang