Can all the following be done in Encore or Premiere and only encode the final DVD compliant .mpg ONCE?

Issolate a number of clips out of a number of separate large .mpg captures,
Put the clips in order with title screens inbetween,
Add video effects (fading video & sound in/out),
Author with a DVD Menu.

I'm worried that if I start using software such as Womble (which only encodes the GOP) to cut all the .mpg's into smaller clips and then joining all the clips ready for authoring I'll start to lose quality due to the amount of encoding that will take place when clips are cut and then put together again.

I've captured my VHS .mpg's at a 15,000 bitsetting and will be re-encoding to around 8,000kbps. I would like this to only happen once, possible with the above method?