Yeah, couple of things I forgot to mention in my haste. The cockpit hatch covers, (lazarette), should always be latched/locked shut. And the companionway covers need "deadbolt" latches on the upper corners, or they will slide/float out.
And yes, the boat can sink. But it would have to be a combination of a few things to make it happen. Knocked down, keeping the sheets fast, big rolling waves, and a bottle of liquor clutched firmly in the hands of the operator. On a lake? Not a chance. And not to resurrect a long debated and tired old post of locking keel pins, but that little keel locking bolt against a 550 lb. keel will do nothing to prevent this. And despite some near National Enquirish internet tales, right alongside "Batboy Terrorizes Chicago", you would be hard pressed to sink, or capsize a C22. The more common causes would be keel cable hose becoming disconnected, holing the hull, (another near impossibility), or run over by a drunk or idiot in a compensation boat..