If you are judging the quality of your image by looking at your computer screen, you will be making bad judgement calls because computer monitors do not properly display video. You must output video to an NTSC monitor. Do not convert the file to progressive. That is not necessary.
Shooting progressive doesn’t help with this situation either, so i dunno where you got that info from. And for future references, definitely do not use the de-interlace filter is FCP. it doesn’t de-interlace anything. it just deletes one of the fields of your interlaced video.
