Answer for #1 & #2: I do not know. Answer for #3: yes, it does. Answer for #4: Yes, it works reliable. If the server is unavailable everything just works fine.

Answer for #1 & #2: I do not know. Answer for #3: yes, it does. Answer for #4: Yes, it works reliable. If the server is unavailable everything just works fine. If the server is available your current position is synchronized so you can continue on a different device.