The calculated basal metabolism for your height, weight, and age is 1700, so you are pretty close to normal.
More mass increases metabolism. The heavier a person weighs, the more energy is needed to move that mass around. However, at rest, someone who is in poor physical shape with a lot of fat and little muscles will burn more calories than someone of the same weight who is far more muscle and in good shape. This is because the body doesn't had to work as hard to get nutrients to all the parts of the body.
If these same two people engage in exercise, the healthy person with more muscle is going to be able to exercise at a much higher intensity, so this is where their increased muscle mass may burn more overall calories.
Overweight people aren't overweight because they have a slower metabolism, but because they eat too much relative to their activity level. If someone eats 1,000 extra calories a day, they will gain weight until their bodies need to burn an extra 1,000 calories to support their increased body mass. This is why people who are heavy have a large decrease in weight loss very quickly when they begin dieting. However, as they lose weight and increase fitness, they will often hit a plateau as their metabolism slows.
Performance is essentially the difference between a persons resting metabolism and their max metabolism. We use heart rate to correlate somewhat to metabolism. The higher a persons fitness level, the lower their resting heart rate, and they may even be able to raise their max heart rate.
Genetics can play a big role in a lot of these factors, however, by recording your stats over time, you will be able to see relative changes.
Well, you have to have a hobbit stomach to eat 2,000 calories in one sitting.
But rice, potatoes, and beans with a nut cheese sauce I make with cashews is pretty calorie dense. I use two cups of cashews and that alone is around 1,300 calories. I don't always eat it all at once. Sometimes I eat until I am full, sometimes I eat until I hate myself, and sometimes I eat until it is all gone:)