1) I would absolutely make sure the dishes were done as fast as possible, to minimize labor costs and opportunity costs.
2) I would insulate the pipes, absolutely.
3) I would also look at seeing if you could slightly lower the temperature of the water going to the dishwasher. But not so low as to jeopardize good sanitation. Make sure you are heating the water just enough, but not more than needed.
Those last two should have no negative impact on the efficiency of getting dirty dishes back into circulation, and passively save you money on energy costs.