Well, did removal of the bench seem to weaken the boats sides? Ive been contemplating doing what you did to my boat for years and the only concern I have is compromising the structural integrity of the boat. Could care less about floatation, way I see it, if I flip my boat or am stupid enough to put myself in huge waves, then I deserve to lose my boat.
Also, which tool did you use to do the cutting? Maybe you could show a photo. Im thinking just using a giant grinder to sand down the rough edges of the cut flush with the sides. Then Im gonna get the boat repainted, and add some sort of "grit" to the paint on the inside for non-slip tracktion.
Heres a tip for ya. I noticed you did not jigsa4 your decking to fit around your ribs, thus you have exposed holes leading to underneath your deck. I solved this problem by getting black pipe insulation. Just cut it to length and push it in the cracks. Your baits and hooks and weights will never end up under the decking again. When the stuff wears out go buy some more, it cost like 2 bucks for 3 feet!