-- Last Updated: Jan-17-13 12:37 AM EST --
The portage at Millville Dam is difficult and over half a mile, from what I've read. Corbett rated the scenery in this section as "poor"; ugly riverside houses, the power plant and a huge quarry operation. A mile upstream of the dam, there is a sizable Class III drop in the midst of flat water above and below; I've heard paddlers have died there, but I believe there is a sneak route at river right.
I've also heard from area residents that the park area below the dam gets regularly trashed and there is an unsavory element usually hanging out there.
I personally would not care to run the extended whitewater above Harpers Ferry in a loaded canoe (though I'm sure it's done at milder water levels). Whitehorse and below would be manageable, as you could pick your way through the rock gardens and avoid the bigger wavetrains. Alot depends on the level. Also, if that section is still the rental zoo and redneck hangout it once was, you'll want to avoid being there on a summer weekend.
Goose Creek is quite a long way down river... how many nights are you contemplating, and where would you take out, the new Kephart landing? (I'm actually working up a plan to paddle the entirety of Goose Creek.)
For an overnight Shenandoah trip, I think you'd be better off going from Watermelon Park (or the Locke's Mill public put-in just upstream), to either the takeout at Shannondale Springs, or a little further to Rt. 9. Another option, which I posted a trip report about here on P-Net, is Morgan's Ford near Front Royal to Locke's Mill, staying the night on one of the river islands along the way.