About the navigation maybe this helps. What I did after trying to get offline maps on my phone and failing was to just take pictures with my phone off google maps from the internet in hotels. Big picks for the easy turning points and zoomed in ones for the bigger towns I would be staying in. This along with my phones gps worked fine. Did get lost a bit here and there but not too bad. I also had a complete driving map book of China which didnt help me in the least. Tried to use it once or twice but gave up because I couldnt find roads in it.

Good luck anyways man