1-2 to be safe and most of those pounds could be water weight.
False, the inventors claims were clearly not well tested
You don't need to be active for a few days because you are still not fully healed yet and you could possibly hurt yourself even more if you begin doing physical activities right away...
Your heart rate might be higher on a regular basis, and your fitness levels may go up because you are training your body and it is adapting to what you are doing. you can monitor it by measuring how far you run, doing blood pressure, checking your pulse etc