RE: Tigermoth on Floats with NO rudder
i have a golberg cub, and a 6' beaver. life was, and would be impossible without water rudders. also step taxiing is a little risky. when i see most guys doing it they aren't truely on the step like full scale. with full scale, you pretty well never get the aircraft on step just to taxi, typically just to stretch out a landing roll to speed up getting to the dock. models dont have the same problem with overheating engines. but step taxiing is risky sometimes. you never turn around in any significant wind, just asking for trouble.
that link says to taxi downwind with the elevator up, that caused my cub to blow over, and i know a fella that lost a full scale cessna 170b that way. you get a gust under the tail and over she goes. neutral or down is the way to go. if you are plow taxiing to make the turn you need to have the elevator up to keep the nose as high as possible to get the wind acting on the nose as much as possible and give the water rudder some traction. once you pull the power off let go of the elevator. as was brought up earlier, sometimes if the plane wont turn, you shuldn't turn. full scale cubs have one rudder because if you had 2 you would be able to turn in winds that would turn you over more often than not. most of our models, even those reproducing larger heavier airplanes like beavers, behave more like cubs on the water.
real float flying takes lots of patients and a sometimes some creativity. less procedure and more technique than some kind of flying.
give your moth a try, see how it goes, it not hard to toss a rudder on later