I thought I'd share some of my experiences with trying to cut some Mpeg2 files. Since I'm a newbie I think this may be helpful for other people like me.

I downloaded a few files that were in a cue/bin format and so called "SVCD" format. I wanted to get the actual MPG out of it so I used "Isobuster" to extract it.

Joining:
I followed the instructions on this site to join files using TMPGenc but I found that it screwed up the audio synching royally. So I scrapped that idea.

Cutting:
Also using TMPGenc I tried the instructions on this site to cut a file. I found that it would not cut the file at the place I wanted. The audio would stop at that correct point and then play some silent video for 10 seconds afterwards. I tried this many times to the same effect and got fed up with it.
So I downloaded BBmpeg and tried that it worked well! Cuts at exactly the place I wanted both audio and video. I used the instructions on this site where it tells you to use TMPGenc to demultiplex the stream, then use BBmpeg to cut. Simple as that.

Anyways, thanks for the helpful information here. BTW, for those of you who also download "files" from Usenet doesn't it bother you that the "files" are formatted to fit on those new 90minute/800mb CD's? I have an older CDR so it won't support them and where I live I don't think 90minute CDR media is readily available. Just an observation and the motivation for me to play with this stuff.