More on #2: When you pick up your permit, ask if there are any available for entry the current day. If there are any, you could then hike up to Lone Pine Lake and camp. That would make a nice first day easy start.
#3. Might still be snow on OAP. Ask other hikers you meet on the trail. New AP is south-facing, should be all dry, and the trail should have no scrambling required.
#4. It is on the way down that the critical switchbacks are missed in the darkness.
