I've noticed saturated fats trigger a far greater sense of satiety for me than unsaturated fats, vegetable oils in particular, which I feel I could eat forever. So my personal estimation is sticking to sat fats over unsat fats will result in eating fewer calories.
I actually don’t think so. When you eat fat AND carbs, you tend to eat more of each than if you would have eaten them separately. Source: I’m Swiss and we have dishes like Fondue or Raclette, where each serving is often more than 200g or more cheese. Which would be a lot on its own, i.e. without bread or potatoes. Might also be because it is melted cheese though.