First, pinching the tire is not an effective way to judge if it needs air.
Second, you shouldn't be pumping it to the max psi of the tire unless you are huge.
I am a casual rider and I ride for pleasure and fitness. For me pinching the tire gives me a good approximation of the level of pressure and if it seems a little low then I fill it up. I usually top up the pressure after every couple of days or 20 - 30 miles of riding.
I am fairly heavy, around 210 pounds, so I prefer to run my tires at max psi which is 120. What pressure would you suggest I run at and why not run at the max?