1. Its definitely possible and with that length of time it can be done healthfully with a loss some weeks of 2lbs and others 3 though generally to healthily lose weight its usually recommended by everyone to not exceed a 2lb loss per week.
2. Its a processed food with a lot of salt in it most likely. It will keep on water weight. As for if its healthy? I'd say it can be part of a healthy weight loss plan but you should really try to limit them to only 2 or 3 per week. When it comes to weightloss creating a caloric deficit through diet and exercise is the main thing you need to be concerned about.
3. Do propels contain a lot of sugar or salt or anything else fattening? If so you should cut back on them but keep them in your diet if they are important for you to have.
Remember to make your weightloss a lifestyle change and keep the foods you want in your diet for that lifestyle change but simply in a portion controlled amount so that you can create a caloric deficit for weightloss.
