The rice mounds should be firm and smoothly coherent. Some of these guys leave rice bits sticking out all over the place, and the rice will fall apart as soon as you pick it up. In Japan, I usually have a little something to eat before or after the sushi shop, because I know I can't afford to fill up on sushi. While sushi is expensive, it is a lot cheaper in the U.S. than it is in Japan. When individual sushi arrives, the chef places it on the wooden tray in front of you.
Some people just pick it up with their fingers, others always use chopsticks.
Typically, you do a little of both. Likewise, filling the sauce dish to the top is a sign of poor taste. When the dish gets dry, just pour in a little more. It is also acceptable to set a half-eaten piece of sushi back on the wooden tray. I am told, but cannot confirm, that people from Tokyo dip the fish side of the sushi in the soy sauce, while people from Osaka dip the rice side.