I’ll go first. After your turn the water off in the shower but before you get out, use your hands to wipe off any standing water on your body. Maybe even give your legs a bit of a shake. This way, you won’t drip nearly as much when you get out, keeping the floor and your towel drier.
The secret to keeping water hot is minimising surface area and, of course, insulation. If you want instant hot water you can actually buy electric hot water tanks with, say, 10-15L capacities that go under the sink so the hot water only needs to travel the 50cm or so. Very cheap and much more simple than instant heaters.