Mostly wrong. If you choose either the temperature or the time at which you want to drink, it only matters that you add the milk "in time" - all other parameters are meaningless.

There is neither a theoretical nor a practical difference. I think it is the first law of thermodynamics.

These kinda post always make me sad becaus they remind me how little i earn relatively to my colleagues. Even though i chose the place i work at and often get offers of positions where i can earn 30-40% more i still get jealous... :/