Water must be warm in order to activate yeast, but not boiling. Boiling water will spoil yeast.
You can replace ¼ of water cup with milk.
You can also replace sugar with 1 tbsp of honey.
If you like a stronger cheese flavor, you can add, for example, little chunks of bleu cheese, on top of the other ingredients.
Try to keep the mushrooms fairly dry. Mushrooms are like sponges, and will lose unwanted water on to your pizza.
You can try different toppings to basic pizza dough, and even add cheese borders. To do so, you should roll out pizza into a larger size, adding cheese one inch from the border, and little pizza sauce. Roll dough over the cheese and press firmly to close.