You may get a drop in service standard once the attendants realise that you are not going to spend an awful lot of money at their restaurants, especially in the bigger, posher ones. Suddenly their smile dimmed, the attitude may took a turn for the worse and you be hard pressed to find one to top up your cup of tea. Good luck!
Many older folks in Hainan still do not like to have their photos taken. There is an old Chinese superstition that the camera carries away a little bit of your soul. If you really want to take a photo after being refused or rebuffed, do it discreetly.
Very peculiar to China, and more so in Hainan. Regardless of whether you are shopping in a mall, or in shop, or in a boutique, you WILL have a shadow perpetually following your every step. Put it down to the zeal of these sales folks trying to convince you to make a purchase, or that they are simply being generous in spirit to offer their assistance, or they are simply afraid you might run off with the merchandise, but I felt it to be very oppressive to have someone tagging you everywhere, even when you are purchasing private items! It got to a point that I purposely walk round shelves to let them get the message.
This is China. Unless you find languishing in a jail as an "off the beaten track" activity to enjoy.