See, I don't know about this "should" business because it all looks really complicated to me and I'm not sure if each of these lines serve a really useful function?

You and me both! I mean, I can say what each line is *supposed* to be doing, but I am still hopelessly confused about whether I need to be doing it.

MPEG2Source("file location", false)

Huh. So you don't even index the file? I actually started off there, but I got a much smoother preview in Premiere when I added indexing.