Re: Workflow for HDV to SD delivery

GoPro footage is h.264 and, for all intents and purposes, should perform in a similar manner to DSLR footage.

In terms of deinterlacing, once you have your segments cut, right click them in the timeline and select Field Order... and you can select "Always deinterlace"

Premiere discards one field of each interlaced frame, and then fills in the gap. You'll lose a little quality in terms of horizontal resolution, but you're also downconverting to SD, so I don't think you'll really notice any real hit to quality by the time you complete processing.

Alternately, you can deinterlace in After Effects with some more robust plugins like Fieldskit or Magic Bullet Frames. Some PC users also use something like AviSynth or VirtualDub to process deinterlacing as an intermediate step. Just food for thought, but I don't think you have to follow this more advanced path for your situation.