My answer will focus on a general analysis of protein intake among all types of people who do all types of exercise and conclude with recommendations for you, specifically, based on the information you have given. Hover over the links to view the full citation, follow them to find the source.
I use a lot of Xg protein per lb/kg of bodyweight in this answer, If you are obese, using a protein intake relative to body weight is a bad idea. You should either calculate your lean mass (overall weight after subtracting fat mass, which can be calculated by body fat percentage) or use your goal/target weight for calculations.
The crux of this problem is "how much protein will be absorbed by my body and how much will be ejected as waste?" It is commonly known that if you eat too much you will absorb the calories and 'eject' the un-absorbed protein.
As quite rightly pointed out in the comments, One gram of protein per pound of body weight (1 g/lb) or 2.2 grams per kilogram (2.2 g/kg) is the traditional recommendation for protein intake. However, this can be considered the upper bound of target intake, with the suggested range spanning 0.45-1g/lb.
Protein: Athleticism and Body Composition
Two Studies in Phillips SM (2004) Cambell WW, et al (1991) indicated that 12-15% of calories from protein is sufficient for active individuals (60-75g of protein for an individual eating a 2000 calorie diet). However, more recent studies Lemon PW, Proctor DN (2000) and Lemon PW (2004) argue for higher intake - the 2000 study reports that greater than 1.6-1.8 g/kg of bodyweight (0.7-0.8 g/lb of bodyweight) may be necessary, while the 2004 study indicates that up to 3.0 g/kg of bodyweight (1.4 g/lb of bodyweight) isn't harmful, and may have additional minor benefits.
According to the International Society of Sports Nutrition, protein intakes of 1.4-2.0 g/kg of bodyweight (0.6-0.9g/lb of bodyweight) for physically active individuals is not only safe, but may improve the training adaptations to exercise training. The American Dietetic Association, Dietitians of Canada, and the American College of Sports Medicine also support high protein intake for active individuals in the range of 1.2-1.7 g/kg of bodyweight (0.5-0.8 g/lb of bodyweight).
The reasons for the above recommendations are outlined in Wilson J, Wilson GJ (2006) and Campbell B, et al (2007) and focus on the increased leucine oxidation (a marker for amino acids being used for fuel, by being turned into glucose) that requires a higher intake of amino acids to negate and preserve nitrogen balance.
Additionally, Jeevanandam M, et al (1986) explains that increasing protein intake above the US RDA 'daily allowance' of 46-56g for adults (female/male) will increase protein synthesis and, at levels higher than double this total, decrease protein breakdown. Increased muscular hypertrophy is seen as beneficial to sports performance.
Protein: During Weight Loss
A study of obese and pre-obese women by Leidy HJ, et al (2007) and a study of atheletes by Mettler S, Mitchell N, Tipton KD (2010) both showed that high protein diets have been found to preserve lean body mass when dieting. In addition to these findings, Layman DK, et al (2005) concluded that a high-protein diet improves overall body composition.
A study of healthy men by Pikosky MA, et al (2008) found that a doubling of protein intake from 0.9g/kg (near the daily recommended intake for the general population) to 1.8g/kg is able to preserve lean muscle mass during short-term and relatively drastic drops in calories.
Protein: What is too much?
A meta-analyses of 35(!) studies by examine.com concludes the following:
Don't worry about it if you have healthy kidneys and control your
protein intake if you have damaged kidneys. It may be prudent to
gradually increase protein intake to higher levels rather than jumping
in both feet at a time, but there isn't much on this topic.
It is generally recommended to consume more water during periods when
protein intake is being increased. Whether or not this has biological
basis is not known, but it may be prudent to do
Protein: Your specific question
To summarise, you are eating at a 45/35/25 split which is the standard recommendation for someone who is weightlifting and looking to gain muscle. It provides you with the protein you need to develop muscle in recovery, and the fats and carbohydrates you need to function and have energy.
You estimate your BMR at 2700-3600 per day. This strikes me as a lot. Plugging your height, weight, age and gender into the iimym BMR calculator I get a BMR of 2064. With an average difference between my estimate and yours of 1000 calories, I recommend you have another look at how you calculated your BMR and perhaps re-do it across lots of calculators to get a sensible average.
Note: If I plug in your exercise data I get a TDEE of 2500 calories per day.
We shouldn't be the rock and eat 400g protein per day. Looking at the information I have presented above and the studies referenced it's fairly clear that your macronutrient breakdown (ratio of carb/fat/protein) is fine. What is made clear is you should perhaps look at how many calories you are consuming, below is one sites (iimym.com) recommendation: