Hi,
as far I can remember, the hotel has a 24 hour reception service (as pretty much every hotel in Guangzhou).
Obviously you will need to pay for the night. But if you let them know in advance via email that you will arrive late at night, it shouldn't be a problem.
Further, if your plane lands at 10.30pm, its unlikely that you will make it in 1 hour back to the hotel unless you have a dream run at the airport (customs, visa control, etc....)
Not far, but not within walking distance. You can take subway from Guangzhou East Train Station to Zhujiang New Town station. It's only couple stations away from the hotel. You can take train from Shenzhen to Guangzhou East Train Station. The hotel is just located at opposite road.
