Also, when you have two kids carry a mushroom to the bin, by pausing and dropping two kids on one mushroom, does this count as two mushrooms toward the Fungus Among Us award?
It should. Doubling (Tripling, quadrupling) mushrooms is almost certainly a glitch, so I don't see why the programmers would go to the lengths of making sure that only one pickup counted to the award per mushroom spawned, when it seems that the behavior was not anticipated to begin with. Certainly it counts towards food, or tech points in the case of other collectibles.