I'm going to make some general comments about new boarders and board size vs weight. This is most certainly NOT meant to be negative. Can you tell I'm a little nervous about discussing girls and weight?
As has been stated, 152 is on the short side for 200 lbs. If I thought you were going to be hauling ass and trying to make carve turns, I would say don't even bother. But the reality is that for your height, your a little overweight (sorry...it's relevant). Most of the time people who are carrying a few extra lbs aren't going to be as motivated to go really fast on steep terrain. Falling hurts more at speed, and that tends to take the fun out of it. Go have fun with the board you have. It may actually be better, because it will take less effort to control and won't wear you out as quickly.
I think your weight target is spot on. My wife is 5'5" and looks and feels great at 140 lbs. Assuming you reach your goal, the board you have will be perfect. Even if you don't, the board may well work for you anyway, just depends how fast you ride and how steep the terrain is.