New hrm, just got off treadmill. Anybody explain my stats??

Everything is an estimate. 72 for walking with no incline sounds about right but maybe low by 10-20% depending. 357 sounds decent for 40 minutes with your HR in the aerobic zone. You were somewhere around 75%MHR, which is great... it means you were working hard but not too hard for a sustained effort. Somewhere around 400/hour for hard walking sounds right to me for your weight (I weigh only slightly more than you do and burn about 700/hour running with a similar HR).

Don't worry about the "fat burning zone" thing. It's an area where you're burning a higher proportion of fat vs. glycogen (stored sugar, basically), but as you increase the intensity, you burn a higher amount of glycogen vs. fat, but you burn more overall calories. So, say for instance, you burn 100 calories in the fat burning zone and 60% come from fat and 40% come from glycogen. You've burned off 60 calories of fat. But in the same amount of time, by bumping up the intensity, you could burn 150 calories but 50% come from fat and 50% from glycogen, well you've just burned 75 calories from fat and 75 calories from breakfast or whatever. Better to burn higher. You burn fat all day long as you do low intensity moving around - walking in the grocery store, mall, moving around your house etc.

Use the numbers you get from your HRM. If you don't lose weight accordingly, adjust them slightly. What is your weight loss goal set to? How many pounds/week?

So do you have your MFP goal to lose 2 lbs/week? If so, count 357 and eat them all. 2 lbs/week is aggressive for someone with only 20-30 lbs to lose. You're better off aiming for 1 lb/week... or maybe 1.5. But if your HRM is overestimating at all, it's just fine to eat them all if your goal already has you eating at a 1000 calorie deficit each day.

357calories for walking sounds pretty high. Are those net calories burned? I burn 350 for 50 minutes of running. :O

So do you have your MFP goal to lose 2 lbs/week? If so, count 357 and eat them all. 2 lbs/week is aggressive for someone with only 20-30 lbs to lose. You're better off aiming for 1 lb/week... or maybe 1.5. But if your HRM is overestimating at all, it's just fine to eat them all if your goal already has you eating at a 1000 calorie deficit each day.

Maybe u can make sense of this?
If I go into update your diet profile, I have two lbs listed a week but if I go into my goals, mfp only gives me 1.1

So then MFP has given you a target of 1200 calories, right? MFP's lowest target is 1200, so if you put in that you're sedentary, it assumes you burn less than 2200 calories/day required to allow a 2 lb/week loss. So if it's estimating you'll lose 1.1 lbs/week, then it assumes you'll have about a 550 calorie daily deficit... or your estimated sedentary total burn (before exercise) is 1750/day. If it estimates you burn 1750/day, you'd need to eat only 750 calories daily to lose 2 lbs/week, which is way too low.

So eat the 1200 plus all your exercise calories and see how much you've lost after a month. If you find that too hard, bump up to 1400 plus exercise calories. That will reduce your deficit to a bit over 1/2 lb weekly loss, BUT... only those who are disabled or housebound are truly sedentary. You are more than likely lightly active anyway, and your TDEE is probably more than 1750/day at 150 lbs.

357calories for walking sounds pretty high. Are those net calories burned? I burn 350 for 50 minutes of running. :O

Oh, you are being badly under-estimated, unless running really slow, like 3 mph perhaps.

Even if 5 mph, that's going to be about 540 calories gross.