Depending on your weight and body fat percent, there is probably nothing wrong with your decreased appetite. Your body could be finally off the carb/binge cycle and now you are using excess fat for energy. Expect your meal habits to "normalize" when you get closer to your body's ideal weight and composition.

With eating less food, you're bound to poop less, so again it's probably not a problem.

I went through some weird poo phases too with paleo, oddly around month two. Same prob, I was suddenly only going every couple of days. Things normaled-out again after a while. It's only been two weeks - your body doesn't know what's hit it yet :) As for calories, that's the glory of paleo: eat when you're hungry, and stop when you're no longer hungry (I don't call it "full" anymore, as it feels so different from full.) Your bod will tell you what it needs.

It seems to me that you're doing great. As long as you keep feelign good, let your hunger guide you. I had eggs this morning, and haven't eaten since (about 9-10 hours). Normally, I don't eat until around 4pm (unless I'm hungry...). Some days I will eat a lot more.

As far as the pooping goes, I started taking "natural calm" magnesium (to help me sleep), but it seems to regulate me pretty well too. Again, though, if you feel good, why worry? So long as you're not crampy, painful, etc. I wouldn't worry. Remember you're also eating a lot less so there is less to digest.

As your body's metabolic processes heal and normalize you will notice a lot of changes. Eating nutrient dense food when your body needs it can mean eating what seems to be a lot less than on SAD, the high quality of the food you eat now is more important than the quantity. Your body may be burning some fat stores and that counts as your daily calories too. Physical activity level plays a role too, if you are not too active daily you don't need as much food. As for pooping frequency that can vary once your body adapts, you will poop when you need to not when you mind 'thinks' you should based on years of a dysfunctional diet. After 100s of 100s of years of evolution your body knows what do do when it's given what it really needs, trouble is our 'modern' minds tend to interfere and we try to second guess nature.

I am able to work from home a lot and when I do my body just does not need a lot of fuel, as I get up, walk a few feet to my desk and begin work, no need to be up early to fight traffic, etc and no need to pack a lunch. My body will just naturally not ask for a lot. I normally vary between 1-2 meals a day and some days nothing at all, what matters is it will all balance out over time, worrying about a day is pointless.

I think that regular bowel movements keep our intestines thriving with beneficial bacteria. You want to keep that train moving! I would suggest adding more raw greens, at least one big salad a day with your fats and proteins, and see if that helps. Adding some chia seeds into your diet can also be very helpful in this arena. Are you drinking enough water? The general rule of thumb is to drink half your body weight in ounces of water as a baseline, more if you are sweating a lot, or taking in diuretics. Dehydration will definitely slow that train down. Your new diet can have so many detoxifying effects, but only if you keep all elimination pathways open!

I'm sure if I ate three times a day, I'd never feel hungry either. I usually eat at most two meals a day, often only once, and every few weeks or so, not at all. Perhaps you should lose the "three meals a day" approach (which there's nothing paleo about, IMHO), and instead just eat when you're hungry.

And you mention constipation, but it sounds more like you just don't need to go as much as before. Nothing at all wrong with that. Constipation is feeling like you have to go but can't. Big difference.

And regarding grass fed beef being expensive, definitely look into either ordering some in bulk online or perhaps taking a drive out to a farm in your region (check eatwild.com) and buying a ton at once. Very cost-effective this way, I have found.