Lets just stick with the basics..
1. Creatine is creatine. The chemical genetic makeup of the expensive GNC brand is identical to the inexpensive Wal Mart or Target generic brand.
2. You would take 10 grams or 2 small scoops (Scoop is provided and is 5 grms) for the first week, then 5 grms a day after that. Some take it after excercise with grape juice, I don't
3. It is irrelevant what carbs you will be using at any given time. What is important is that you watch your carb intake, keeping it mainly complex carbs and under 50g a day while losing body fat. Take 1 grm of protein per pound of lean muscle mass per day to keep your muscle. Resistance training is needed to keep your muscle while cutting calories/carbs
If you excercise, and keep your carbs to 50 or below, the weight will come off. All the other stuff is not that relevant