Hi ak47,
The min bitrate really depends on what your player can handle. I like to maintain at least a very low constant bitstream (ex: 64Kbps), instead of going down to 0. Actually in a movie the minimum bitrate never goes below 250-300Kbps throughout the complete movie.
Also 3,000Kbps MAX should be adecuate for most MPEG-2 encodes. With KVCDx3 (528x480( 576 ), there's really no need to go beyond that, specially if adaptive filters are used. Of course, if the encoder used is garbage, then the result won't be very good on high action

But based on the facts that we have been able to prove and the many encodes that we have done, I think that the results that TMPEG has provided should be a reference to the industry so they can measure their products (encoders).
It's up to the industry if they want to apply all the research/methods, etc. that we all have done
-kwag