Question

a higher rate of metabolism means a faster breakdown of fats, and therefore, it besides reducing belly fat, it prevents the storage of fats around your stomach."

Answer 1

metabolic process in the body uses the energy (calories) for everything (cellular absorption, physical exercise, etc..)

so when metabolic rate increases consumption of calories increases too leading to burn fat around stomach and wherever else. More over, weight loss depends on creating calorie deficit which is caused by normal or high metabolism.