Dalian, china, Accommodation on Islet and return trip

Please do not worry. You can can find some hostles to live there.
For the returning time, it is suggested to ask the local people on Haiyang Islet, because they know the exact time.
For the facilites, what kind of facilities do you want? Generally speaking, the condition is not bad there and almost all of the facilities such as Internet and showers are availale there, so enjoy your trip there.