I am not an expert in the subject so this is just my thoughts on the subject.
The conflicting g/pound depend on your fitness program. The 0.5 g/pound is meant for the average person who doesn't do heavy lifting. The 0.8 and 1.0 g/pound is geared more for those who lift heavy and bodybuilder type workouts.
I have heard that your body can only process about 25g of protein at one time. However, I don't know how long you have to wait in between meals containing 25g of protein. Seems like 3 hours would be a safe time to wait.
I have also read and heard that higher protein intake helps shed fat and support lean muscle mass. While I believe that is true, I have a hard time keeping up with a diet that includes too much protein. I tried following a 40% carb, 40% protein, and 20% fat diet for awhile and just was not happy (and my digestive system was very mad at me). By not happy, I mean I felt like I was missing out on so many other types of food and I just am not the type of person that can live without variety.
I am sure others on here will have more information (and perhaps more accurate) but for what it's worth, I hope I helped a little.