I agree on the Field Order suggested by Devil. I've run into some serious comb artifacts trying to use frame rendering for NTSC video, especially when freeze-framing using the Pause button on the DVD player.
Here are the settings I use for the DVD's I've produced with MSP7:
NTSC drop frame (29.97 fps)
24 Bits, 720 x 480, 29.97 fps
Field Order A
(DVD-NTSC), 4 : 3
Video data rate: Variable (Max. 6000 kbps)
Audio data rate: 224 kbps
MPEG audio layer 2, 48 KHz, Stereo
These settings are compatible with DVD Movie Factory, so it doesn't have to re-encode the video when burning the DVD disc image.
Regarding stretching, the 720x480 from DV is a non-square pixel, while the NTSC video is a square pixel, so the stretching is automatic and reproduces the original subject material's aspect ratio.
Regarding playing on all DVD players, the only troubles I've run into are that I burn DVD+R rather than DVD-R, and having the bitrate too high. I've had two reports of my DVD+R's not loading (strangely, on the high-end DVD players). If the bitrate is too high, it causes pixelation when playing, but my experience is that the people that have a problem with my 6000kbps maximum rate also have problems with store-bought DVD's as well.
I'm no expert, by the way, just what I've learned from a little experience.