Can the blade get dull more quickly if keeping inside the razor or not?
Same here, except I've never flipped the blade. And I only disassemble my 3-piece razors when I clean them with Scurbbing Bubbles and a toothbrush.I loosen the handle and rinse well under running hot water, leave the handle loose and set the razor down on its side, where a blade tab would be, to drip dry on a folded tissue. Before the next shave I disassemble the razor, flip the blade and carry on.