I'm going to research the question about gluten and come back with something for you guys.
As for the first question, there is so much evidence out there about this already I don't think I need to address it. Obviously you want to take in some decent protein after any strenous exercise. According to your needs you should also be taking in some post-exercise carbs to refuel glycogen and to help your body heal up. It seems like people forget but our body does use carbs as our main source of fuel and theres nothing wrong with taking them in when you're not exercising, the key is in moderation. If you're trying to lose fat, smaller portions are always gonna help you burn more. I don't buy into the paleo train of thought at all and if somebody is going to tell me that eating rice, potatoes and whole grains is bad for me i'm going to tell them they're fucking crazy. The key about carbs is eating according to your needs. I generally eat more carbs pre and post exercise and in the morning and this system has worked well for me when i'm trying to lose fat. You could also just eat the same amount of carbs throughout the day and it might not make any difference. Unfortunately, i'm not aware of any scientific studies that have investigated into the effect of carb cycling along with a training program so theres no way to know. To me though intaking carbs before and after you're going to exert alot of energy seems like a fairly intelligent way of going about things.
Personally, i'm at 160lbs and around 10% bodyfat and i'm trying to cut to 155lbs. I'm currently eating about 1800kcals a day. I try to take in about 40-50g of fat day, ~100g of carbohydrates and around 150g of protein. If possible all from high nutrient value foods. My fat sources would be olive oil, fish oil, a small amount of butter, dairy, occasionally a small amount of dark chocolate or pure cocao, nuts/seeds and also some other animal fats. Carbs are mostly from fresh fruit and vegetables, oats, rice and other whole foods. I don't see a problem with refined sugar in a post workout recovery shake either. Proteins would be whey, casein, dairy, eggs, meat, nuts, seeds and occasionally tofu. For me this works great, i've good energy levels and I don't get sick of my food by being overly restrictive. Generally speaking, I definitely think for athletes you want to be taking in some carbs all the time, particularly pre and post exercise. I don't see the point in demonising them. They are our bodies prefered energy source and we will burn them. The key is portion control and eating according to your needs though and some people can't do this!