My neighbour is a retired commercial pilot with hundreds (if not more) of hours experience flying "Beavers" in his early career. He does not see an issue with using an electric powered float plane for short hops.
As to the weight issue (I am not a pilot and only speaking from what I think is "common sense"), float planes often take off and land multiple times on one trip. Often the first landing will be with the plane fully fueled (only a small amount burned) and loaded with a full load, so based on that, (and not knowing the actual weight differences between the electric and the conventional versions or any "adjustments" that may have been necessary to the aircraft) I wonder if the weight added? (don't know but suspect the electric would be heavier due to the batteries) for landings would really be a major issue? I think I will ask my pilot friend next time I see him to get an informed opinion.
Just some thoughts,
Tom