Code or no code I would not have run flexible tubing of any kind through the floor, or a wall partition. I don't like it coming out of the floor at right angles to the stuff that will be moved around it even if it's hard piped. I would have ran hard pipe from the source of fuel with it inside the wall, brought it up about six inches from the floor, installed a 90 and had the nipple come our of the wall a couple of inches past the wall, and put a shut off there at the end run of the hard piping, then hooked the flex line to that and on to the heater. I would have only used one male female 90 on the hard pipe into the stove. You have right there what I would casually refer to as a "plumber's nightmare." It'll work like you have it but and I'm being kind here, it looks quite a lot like windshield wipers on a duck's butt!