Some thoughts.
Most kits have some right thrust built in, some more obvious than others. Not having it won't make it erratic but will require some more rudder during takeoff runs.

You said you intend to fly it on floats, I do a lot of float flying, I have 2 giant scale and a bunch of smaller float planes so I can speak with some experience. If you have the option to fly it off wheels first do yourself a favor and use that to get familiar with how the plane handles and get some run time on the engine if its new because you want the most reliability you can get.