Question 1 - Does toast really fall butter side down?

Short answer - sometimes.

Long answer - the act of dropping toast often involves it flipping over the edge of a plate. Normally when on a plate, the buttered side would face upwards and so the flip will lead to the buttered side pointing downwards. Given enough of a drop, it may rotate again but, since toast drops would typically involve only two or three feet of falling, one would expect a landing before that could happen. I would therefore expect a greater number of buttery impacts than non-buttery.