I have been adhering to LeanGains for about a month and a half now (despite loosely), but here's what I got:
1. Important. Protein is very important in building muscle, especially right after the workout. Plus high protein should help with satiety. But it also depends when you're eating..for example I'll get >100g protein after I workout because I workout fasted. But if you have a small meal before you workout, then eating 100g of protein isn't recommended.
2. If your goal is just weight loss, maybe LeanGains isn't for you. What's your current bf%? How long have you been eating Primal/Paleo? If you're new to Paleo, you might benefit more by just doing HIIT or something. But if you have <13% bodyfat this protocol can definitely help.
3. How much do you weigh? My understanding is that the Leptin reset protocol is only for obese individuals (or once obese) that had all their hormones messed up. If you're more or less in shape and not overweight you don't need to worry about Leptin.
4. LeanGains involves calorie cycling by definition. Standard body recomposition is -20% on rest days and +20% on workout days. This will help.
5. They're more of guidelines. Obviously if you want superior results you'll follow his program to a science, but for most of us I can assume this would drive us crazy having to calculate every calorie at every meal. Personally, I don't worry about the exact numbers but try and use it as a ballpark number. But getting the necessary calories is important -- log some sample meals that you'd normally eat to see how much you should be eating on these days.
6. If you aren't trying to build muscle, then eating a lot of carbs definitely isn't necessary. But that's kind of the whole point on LeanGains. Either way, don't fear carbs on workout days. I'd eat ~150 carbs on workout days if you don't want to go carb crazy, but LG recommends eating around like...400 grams. The rest days will cause you to lose BF% by eating Paleo style with less calories, so if you follow the LG program you won't gain fat.
It sounds like you don't really want to do LeanGains beacuse you'd have to control so many factors. It might surprise you -- follow the program for a month and if you don't like it, then ditch it. But if you don't want to deal with the micromanaging at all, then LeanGains is not for you.