inflating by 2 psi over the door recommendations will not do any harm to the tires. ive been running about 40-41 psi in my tires for over 5,000 miles now without any trouble. i had to replace one so far because a pothole caused sidewall damage, but that was mainly my fault for not noticing the pothole to begin with.
having your tires about 5 psi over the manufacturer recommendations will provide a different feel while driving. the steering should feel more balanced and turn-in will be better. you'll notice a slightly harsher feel over bumps, since the accord is notorious for road feel. you'll feel the road even more with higher tire pressure. gas mileage improvements will probably be negligible. maybe 2-3 mpg at the most, but with today's prices it might be beneficial depending on how much you drive.
my gas mileage is consistent at 26-28 mpg with 70% city, 30% highway driving. thats a result of changing driving habits to coast more and stay at the speed limit on highways. maybe the tires have something to do with it too, but last time i filled them up was when it was about 85 degrees out a couple of months ago. tire pressure does reduce about 1 psi every 10 degree drop and vice versa, so the 2 psi increase would help in a 20 degree drop to ensure your tires stay at the door pressure. another reason i increased my pressure is that the tires always seem to look a little underinflated at 35 psi cold, so i pump them up to max sidewall, which is basically the maximum cold tire pressure.
hope this helps. adjust your pressures in small increments and stick with what feels right to you.
