Optimal encoding with FFmpeg for DVD

[pojke]

I want to convert mp4 videos (typically around 135 mins) to mpeg2 with best quality possible while still fitting on single layer DVDs.
I found the parameter below in another thread.

ffmpeg -i clip.mp4 -f dvd -c:v:0 mpeg2video -bf 2 -mbd rd -trellis 2 -cmp 2 -subcmp 2 -intra_matrix "8,8,9,9,10,10,11,11,8,9,9,10,10,11,11,12,9,9,10,10,11,11,12,12,9,10,10,11,11,12,13,13,10,10,11,11,12,13,13,14,10,11,11,12,13,13,14,15,11,11,12,13,13,14,15,15,11,12,12,13,14,15,15,16" -inter_matrix "8,8,9,9,10,10,11,11,8,9,9,10,10,11,11,12,9,9,10,10,11,11,12,12,9,10,10,11,11,12,13,13,10,10,11,11,12,13,13,14,10,11,11,12,13,13,14,15,11,11,12,13,13,14,15,15,11,12,12,13,14,15,15,16" -aspect 16:9 -s 720x480 -r 25 -g 15 -b:v:0 8000000 -maxrate:v:0 8500000 -qmin 1 -lmin 175 -bufsize:v:0 1835008 -packetsize 2048 -muxrate 10080000 -b:a 192000 -ar 48000 -c:a:0 ac3 -map 0:v -map 0:a -map -0:s clip.mpg

but the comment there was that its matrix was "suitable for very high bitrates."

I experimented, comparing it to this WinFF DVD preset:

ffmpeg -i clip.mp4 -f dvd -target ntsc-dvd -r 30000/1001 -vf scale=720:480 -aspect 16:9 -vb 8000k -g 12 -mbd rd -trellis 1 -flags +mv0 -cmp 0 -subcmp 2 clip.mpg

The first parameter seems to work better because it actually produces a file close to the bitrate I specify while the winFF one doesn't.
But the first one produces a framerate of 25fps, and the 2nd one produces 29.97fps. Which is best for DVD? (my source files are 30fps).

Also, I've read that 2-pass encodes can be higher quality and will be sized fit the DVD more precisely. How do I specify in the parameter that it should be 2-pass?

I already know how to calculate bitrates and author DVDs, so ultimately I'm just looking for the optimum 2-pass VBR parameter for what I'd like to do.