I will get to the specifics later on so that I can specifically prove my point with factual numbers opposing worrywarts comment to my prior statement. For now:
Low carb is preferred, I never stated that you should shoot up your protein immensely, only that you should increase it. Your muscles do need to repair after all. Simple carbs will have the same weight gaining effect if you don't use it all up.
The majority of your exercises revolve around cardiovascular activity correct? Dancing, step, running, stair master, etc, all are exercises that requires stamina and long term muscle usage. Your body doesn't just use "calories" in general for energy regardless of what you do. Based on the type of work out, your body uses different sources of energy.
Carbohydrates is your body's majority source of energy required when you are doing intense anaerobic exercises such as heavy weight lifting (i.e. bench pressing) or playing american football (short infrequent sprints pressing against weight). You don't do this too often, you have circuit training, but I would put that along aerobic exercise as opposed to anaerobic, thus, this means you don't need a surplus of carbs.
Fat is your body's major source of energy when you are doing cardiovascular activity, this is the reason why it is always suggested to do aerobic exercises to lose weight. The process of your energy metabolism is somewhat complicated, I will explain the Kreb cycle and how it uses carbs vs fats later on if you are interested. If not, take my word that your body "chooses" to burn fat over carb when you are doing those cardio work outs. Since you have a high intake of fat, while much of it is being burned, but its quite possible that they are closer to balancing each other off then burning off the fat you already have from your body.
Additionally, with the above to paragraphs, you can come to conclude, that your body can be TRAINED to use specific energy cycles more efficiently. Increasing your cardiovascular activity will allow your body to produce the necessary ATP and begin the kreb's cycle faster then the average person doing the exercise, burning the fat earlier on and faster.
Hope this clarifies your confusion with the mixed information you've been receiving from all of us.
I will provide the more detailed numbers later.