You can always add pudding mix to box cake mix to turn it into a pound cake & yes, the recipe can definitely be found not only on allrecipes, but on the side of most box cake mix as well.
Pistacio cake is definitely not the same thing as watergate salad, though they do share the green color & pudding mix in common, that's where the similarities end, lol.
As for whether or not you can turn it into cupcakes, absolutely EVERY cake mix whether homemade or from a box that I've come in contact with can be turned into a cupcake without any adverse affects whatsoever. Instead of baking for 45-50 minutes, start with 18-20 at the same temperature & go from there!