about 1.2 g protein per lb body weight about .25 g fat per lb of body weight and the remainder in Carbs.

After 2-4 weeks assess, and take off about 40-50 g carbs if you aren't losing enough. If you are losing more than 1 lb a week, I'd just stick with those numbers until you plateau for 2 weeks.

Trial and error will be the best way to figure ot your true caloric needs to lose weight. And while you might lose less muscle if you lose weight slower, it will take over 6 months to lose 30 lbs at 1 lb a week. Lose 2 lbs a week then you could be done 3-4 months earlier and gain that muscle back by having a calorie surplus. It will be much more motivating to lose 2 lbs a week than 1.