The reference to larger tires is relative, the rear tire on many race bikes is a 1.5.

As for casing in a skate park or dirt jump being more damaging to a frame, that is only true of doubles and tables at the track as you can keep rolling after the impact. When the juniors, elites or pros come up short in the pro sections they are essentially hitting a wall of compacted dirt. Force = Mass * Velocity so unless you have the same velocity as a pro rider while casing at the skate park the force of your impact is less than theirs. They are on race frames and the frames usually live through the experience while wheels and forks often don't.

Regardless, no one but you can decide if the frame will be fine for your riding style, your height, your weight, etc..