Well, it all depends on the size/type of your tire and the recommended pressure range. For example, I have some 26 x 1.25 (32c) Paselas on a rigid MTB, which are rated 65 - 100 psi, and I run them at 80 psi which falls in the recommended range, so they are fine. Wider tires can be run at lower pressures than narrow tires without risk of pinch flats. I have some Conti Grand Prix 4000 700 x 23c tires that need a minimum of 100 psi to avoid pinch flats. As far as you bursting the tube, it just won't happen; you will blow the tire off the rim first. You can't judge the pressure by how the pump feels, so if you a worried that the gauge is inaccurate, just borrow another pump with a built-in gauge or buy a good digital pressure gauge.