Either way your render is going to be a long one. That’s magic bullet for ya… You could also apply the effect in Premiere and export uncompressed, then let Encore do the encoding. In my experience, Encore has been much faster than Premiere at encoding Mpeg2.
1 Pass vs 2 Pass? Not an exact science. If you have a lot of motion mixed with a lot of static shots, 2 pass will help quite a bit.
The first pass simply looks at the video for low motion shots to allow more data in high motion areas. If your final video is less than an hour, just use CBR 8.
Cheers,
Vince