the seat is armored..or at least it should be. and no. if there would be holes in the seat then there would be holes in the glass behind it
I've seen the Brewster modeled into this game. The cast iron back rest of the seat was split in two by a bullet coming almost straight from the six. The seat didn't have armor, though, so a bullet from underneath could have penetrated the pilots buttock, and, depending on the angle, continued either to the windshield or the instrument panel, or, in a frontal attack, come from between the pedals penetrating the pilot's chest and flattening against the armored back rest. Remember, a pilot wound can be lethal even without damaging the innards. A 30mm cartridge breaking a leg, bursting the bone and arteria, would lead to shock and bleeding to death quite fast. Adding to that there's no room in the cockpit to bend down to make a tourniquet.