what do you think of my plan...

Oh wow really? I had no idea! I went to a fitness spa a few weeks ago and they said that Polar was the most accurate one there was (within a 10% error). Why would it matter about somebody female or male with the polar...it asks for the gender when you set it up. Strange. I also so amazing ratings for it on amazon, where I bought it....can anybody else give their opinion on this? I had no idea it was not accurate.
I have to Polar FT7

Don't get me wrong, I definitely think you are on the right track, just don't take the calorie burn from your HRM as gospel. I started with a Polar FT60 (which is a step above the FT7). One of the big features it has is the ability to "test" your VO2Max, or for you to be able to input your own VO2Max. I never did the custom VO2Max because it requires you to basically lay down, wearing the HRM first thing in the morning as it takes a baseline of your heart rate and figures out your "theoretical" VO2Max.

However, the other option, would be to go to the gym, pay 100 bucks, and be hooked up to a storm trooper mask and run on a treadmill for an hour. This is the New Leaf system (most Lifetime's and better gyms have them) and it will determine your accurate VO2Max, and give you target HR zones. I could then program this data into the FT60, you can't do that with the FT7. So, essentially, with the FT60 you could at least improve the accuracy, because the OwnCal algorithm estimates calorie burn based on your weight, gender, VO2Max, etc.

Here is where I said the Polar FT7 is a good HRM. Polar's are practically medically accurate on measuring your heart rate. I loved my Polar, but that being said, it wasn't a good calorie burn estimator. And, I know this by experience. Early on when I started my diet at the beginning of the year I had a very aggressive weight loss target, ie., a huge deficit. I'd go work out like crazy, burn say 700 calories at the gym, come home and eat 700 calories or so, and if I did that I wouldn't hit my target weight loss. I tested this consistently, I'm a software engineer, I'm a data guy, and my analysis was coming out that my workouts were probably overestimating burn levels (as well as MFP's burn levels).

Which takes me back to my first point. Don't eat back ALL your calories. Here is what will probably happen if you do:

Say you set your goal at 1500 calories (based on your BMR and whatever algorithm your using to calculate it), for the sake of argument say it's pretty accurate. Then you workout and burn 500 calories. Now, you go home, eat 500 calories (say you have a food scale and it's accurate). So you've consumed 2000 calories for the day, but maybe you only really burned 250 calories, and flash forward to the end of the week. Now you've consumed an extra 1750 calories. You probably haven't lost, and maybe you didn't gain, but then do this over for a month, and get disappointed, and throw in the towel. Keep in mind, you're working your butt off at the gym, it's frustrating and I've been there.

So here is what I would do: get a different HRM, my current one is a Garmin 910XT, and it's like 3x's as much money as my Polar was, but it uses the FirstBeat algorithm which definitely seems more accurate from my calculations, or . . .

Use your Polar, log the calories burned as it says, and DON'T eat back all your exercise calories. Eat back half. Do this for a few weeks. If you are losing too quickly, then simply increase your calorie consumption by say 100-250 calories per day until you hit a weight loss rate your comfortable with. It's less frustrating to be losing too quickly (and to simply have to up your cals) then to work hard for a month with no results or possible gains.

So, I know people are going to say, "what about starvation mode?, You're going to stop your metabolism!". Well, over the course of a couple of weeks you won't slow down your metabolism by more than around 10%, and you're dieting so that will happen anyway, and there are studies which prove this. That is, you'll have time to adjust the numbers, and play around with it. What you will find, is as you get stronger and workout more, you will be gradually increasing your calories to enable the continued weight loss (I've done this three times already).

Just for an example . . . My last bike ride was 85 minutes at 18mph average, the Garmin estimated 924 calories. MFP said nearly 1250, and my polar would have said around 1200 as well. From past experience and being a cyclist for a long time, I think the Garmin is much more accurate.

Anyway, hope that helps. Everything from the BMR calculation to the Polar calculation is based on averages. You might fall into average, or maybe not, but you can tune your numbers by looking at the data, you could chart it all in an Excel document. There are even templates for that. It's good that you are interested in tracking, and some people will say you are making this too complicated. But, really, you are just avoiding another post a month from now along the lines of "Help, I'm not losing, thoughts?" or "Help, I'm losing too quickly . . .". This way you'll have data, and you can "tune" your numbers as you go. By the time you hit maintenance, you'll probably have a very solid estimate of your actual BMR/TDEE etc, and you'll be able to maintain more easily.