Subtracting exercise from food tells you nothing useful.
What you need to do is add exercise to BMR + daily activity, and subtract your goal deficit from that.
Your BMR is 1,600. Add about 20% for day to day general activity and that's 1,920. Add exercise of 500/day and you have total burn of 2,420.
A daily deficit of 1,000 would mean eating at 1,420. On average, of course, you wouldn't aim for such a specific value every single day. :)
But then, I'm not sure that your 2lb/week is a reasonable goal. The less there is to go, the slower the body wants to lose it. Generally think in terms of around 3% of what's left to go. With 50lbs excess, that's 1.5lbs per week, or a daily deficit of 750, or an intake of 1,670.
Deb, in New Zealand