If you wish to have your rice to go with other dishes, you should say so in good time, for most of the Chinese choose to have the staple food at last or have none of them at all.
Perhaps one of the things that surprises a Western visitor most is that some of the Chinese hosts like to put food into the plates of their guests. In formal dinners, there are always "public" chopsticks and spoons for this purpose, but some hosts may use their own chopsticks. This is a sign of genuine friendship and politeness. It is always polite to eat the food. If you do not eat it, just leave the food in the plate.
People in China tend to over-order food, for they will find it embarrassing if all the food is consumed. When you have had enough, just say so. Or you will always overeat!