I had a 1981 Starcraft SF16 for about 15 years, the former owner had out a casting pedestal atop the front bench. The right side of the seat itself was cracked and broke free of the bracket that attached it to the hull. I got tired of it it banging around up there and I removed it completely, at first I put a piece of plywood across, with a lip on it so things wouldn't slide off, but I removed it one year with the intention of adding a casting deck but it never happened. I ran that boat for 11 more years with no front bench, with the max hp, in saltwater I never saw any ill effects of it not being there and it eliminated a trip hazard in my opinion getting in and out of the boat from the beach.
On another note, a buddy had an early Loweline V 16ft V hull, he ran an older 35hp Mercury on it and used the boat to check his crab pots every morning. He took out the forward seat on that boat to make more room for crab baskets. He was running out one day trying to beat an incoming storm and was pushing it hard into the waves on the lower river heading into the bay. He went about his plan and pulled in all his pots and returned to the dock, loaded up the boat and found that he had all but inverted the metal on the bow, it had broken four or five of the front ribs but left the rivets and bits of the rib flange but the hull looked like someone had pounded on it with a sledge hammer. Rather than get another hull, he took it to someone who pounded it back into shape and welded the ribs back down to where they belonged. A few months later he busted it up again. The second time he nearly sunk the thing because they had welded the ribs to the hull and several of the welds had cracked thus opening up several hairline splits in the outer hull. He fixed it one more time but it failed again they welded it up again and sold it.
His was an extreme case and if he hadn't been a maniac who had to pound the boat as hard as it would go every minute it was on the water I doubt he'd have had any issues but it shows that if pushed to their limits a hull can fail, but I'd say its unlikely with a 10hp motor on a lake with a normal load onboard. If you were max loaded, overpowered and navigating some rocky rapids, then I'd worry about that front seat being gone but with 'normal' use, any fatigue it may eventually show is likely many years away if ever. I"d worry more if the middle bench was gone where the hull has less structural support due to the taller, straight sides.
