Nautilus Expansions

While I quite like the idea of the Nautilus mob, there are a few things which I would like to see expanded upon. #1: One of the first things I thought of after the reveal of the Nautilus was how you could tow entities behind it on leads. Unfortunately, there are no chest entities in minecraft, so I have two proposals. One: you could allow minecart chests to be neutrally buoyant when being towed by a Nautilus, or two: add a new entity which is like a minecart, but no cart. It is neutrally buoyant, is crafted with a chest in-between two fences, and can be towed on leads behind boats on ice or a Nautilus under the water. #2: The function of the Nautilus as an underwater happy ghast / horse is cool, but I think a system akin to the horses 'stats' such as jump height and speed could be applied. You could breed Nautilus to single out certain characteristics, such as speed or the range of its respiration enchantment like effect (#3). This would give players more incentive to build 'pens' for their Nautiluses and spend time interacting with them. It would also allow the creation of an underwater equivalent to ice boat highways. #3: A respiration enchantment like effect. I think it would be very useful to extend the Nautilus's 'Breath of the Nautilus' effect to entities around it, only at a much weaker extent - for instance it might take 3 times longer to drown. This could interact with the breeding 'stat' mechanic, in range and strength of the effect.