Hiking Gubeikou to Jinshanling

1) We want to hike form Gubeiko to Jinshanling ant towards Simatai (as far as possible and back to Jinshanling. Is it possible (heard of military zone between Guebikou and Jinshanling) and how long will it take?

2) We've been to Jinshanling some years ago. I remember coming from the parking space there ist an east and west part. Are both parts walkable?

3) Is it better to do the route from point 1) the other way round, means Jinshaling towards Simatai and back and than towarss Gubeikou. Reason: Not so many tourist at the Janshling section in the morning. But maybe that's an illusion because we want to hike during Golden Week in Oct.
Thx for answers