Hungry shortly after eating

Not really normal. I have had the same thing I think it was all in my head. I just have a bottle of water & keep myself busy & it usually goes away.

Consider adding fruits, veggies, salads they help you feel full, not to mention all the good nutrition. Drink lots of water with your meals too.

Play with your macros, find out what keeps you full. I do the water thing too. If I'm hungry and I don't think I should be, I drink a big glass of water and if I'm still hungry 15 minutes later, I have some veggies. I also usually have gum handy. I find chewing a piece will sometimes be enough to remind my body that it just ate and is fine.

It's not exactly normal, IMO -- you should be able to lose weight without being hungry -- but it can be normal when just starting out. You just have to stick it out and it will go away once you adapt to your new habits.

That said, I'd also double check your calorie goal and play around with food choice if the issue continues. For example, if it's an MFP goal, do you know that's pre-exercise and exercise calories are to be eaten back (although most don't eat back all)? Or if you don't have a lot to lose trying for a larger loss per week can be too much (and hurt other goals, like maintaining muscle).

How active do you have your profile set at? For instance our coworker just set up an account and he had his to highly active. We told him that he wasn't in construction and that walking around all day (I admit, we walk around a lot... 10+ miles a day, easily) is not physically demanding. I have mine set at lightly active, and that's accounting for all the stairs, walking, and gym time.

It depends on your activity. If you are working out more then yes, this will help increase your metabolism. Having more muscle helps your metabolism as well--the more muscle you have the more fat you burn at rest which speeds up your metabolism.
I would use a macro calculator to figure out what your specific macros should be. I'm a member of Eat to Perform and they have a calculator on their website anyone can use, but there are others like IIFYM, you can just do a search for macro calculator and find some. It just depends on what your goals are, I want my workouts to be better and to lift more weight and lose fat (not weight necessarily) and I found that Eat to Perform works best for me and by bumping up my carbs and overall calorie intake it has helped me a lot to gain more strength and lose a couple of inches. If you're looking just to lose weight and/or fat IIFYM might be a good calculator. You might need to just try a few things to see what works for your body, but remember that it takes a while for your body to adjust and normalize so don't get frustrated if you don't see results overnight.

If your tummy is growling, you are hungry. If it isn't, i.e. feels hollow or a feeling in your neck, chances are you are thirsty instead. Like the posters above recommended - try drinking water. I've heard Registered Dietitians recommend half your body weight in ounces is the real amount of water we need. 8-8oz glasses is a good start, but most of us need more. Especially if we are trying to lose weight - we need that extra cleaning power to get that junk out

If it says you'll lose a pound at 1600 calories, yes, you'll lose a pound. It's an average though, so you've got to track your progress over time. Since you're in the last stretch of under 20lbs to lose it's going to come off slower. Also, I looked at your diary and noticed there hasn't really been logging done... I don't know if that's accurate or simply a privacy setting getting in the way. If you aren't logging, you should do that. Use a scale and account for everything you eat. That's the only way MFP is actually going to help you.