Doug -
Here's the thing - ideally you want to eat as many calories as you can while still eating few enough to trigger weight loss. Why? Well ... when you reduce calories, your body adapts to the fewer calories - it's called metabolic adaptation. Now, when you reduce drastically, you're still going to lose weight - the so-called "starvation response" doesn't happen as fast or as intensely as most people think it does. But, your metabolism still adapts and slows when you reduce intake, which will eventually start to slow your weight loss.
So ideally you want to reduce what you eat, while eating as much as you can in order to keep your metabolism as high as you can. Make sense?
Also keep in mind that as you lose weight, you'll need less food - it's just common sense that someone who weighs 300 lbs needs more food than someone who weighs 250. My rule of thumb is that every time I lose about 10% of my weight, I readjust my calories accordingly.
As far as the other stuff the protein and so forth - protein is the most important macro here - it will help you to skew the weight loss more towards fat and less towards muscle. But overall, all the figures are estimates, so don't freak if you're up or down on individual days. It's the trend and average over a few days that counts.
For example, my lean body mass is about 113 lbs, so I should be eating around 113g of protein per day. Yesterday I got 124g. Day before I only got 102g. I don't freak out about it on a day-to-day basis, as long as over the long haul, I average around 115g.
Same with fats. Today you may have gotten 115g, but tomorrow you may only get 70g. Just keep an eye on things and make sure that you're not exceeding EVERY day ... eat for the long haul view and not obsessing from meal to meal or day to day.
Hope that helps!