ridewithgps.com is way better for working on a ride and trying alternative routes. Just do one day at a time as separate routes.

For deciding routes based on elevation, pull down the Map menu and select Terrain. If you zoom way in, it shows contour lines every 40 feet, and darker lines every 200 feet. As you draw the route, it updates the red elevation graph at the bottom, and totals on the top right side. You can hover over the red graph to see elevation and grade at any spot on the route. And you can select a smaller part of the route by dragging on the red graph. Then the distance, elevation, and average grade at the top right will show just that section.

It's fast to try a road, then Undo it and try a different one.

Overall, ridewithgps is pretty accurate on grade percentages. But on mountain slopes, it can be off locally, showing a steeper grade than the actual grade. Since google maps guesses the actual elevation between known points, steep hillsides can affect the actual elevation enough to make an exaggerated grade percentage.

For a cue sheet, I usually copy and paste the left side cue listing into a spreadsheet program and edit to suit me. Printed maps are always a problem. I usually make a screen shot and edit the maps. It's hard to get a lot of route on a page and still see the road names. For a long ride like yours, I'd buy some real maps and draw in your route.

For instance, on this Blue Ridge Parkway route, you can drag just the climb starting at 9.4 mile mark, and see that it's 1380 feet in 4.5 miles, average 5.6%. And you can see the local grades as you move the cursor along. (The 18% grade is where the road goes through a tunnel, but google thinks it's going up and over the ridge.)