As far as the hotel expense goes it has nothing to do with per diem. Per diem is a deduction for food and entertainment only. If you had to pay the hotel , you could deduct perdiem plus the hotel cost. If your food and entertainment is more than $52 you can deduct the actual amount, but be sure to have reciepts.

Its M&IE (meals and incidental expenses) that the $52 counts towards. I'm not sure what an incidental is. Opus X cigars for everyone?

meals and incidentials/entertrainment. My main point was that hotel expenses are additional to per diem and are deductible.