First Let me say that I am super excited for the New installment of Starcraft 2. Heart of the Swarm looks amazing.
Anyways, On to more important things. I qualify this skill as a Fundamental because it is a skill that will significantly improve your over all game play. Having workers and structures on Hot key allows you to instantly target them, and cue workers, units or to build structures as opposed to selecting a worker out of the crowd which takes time. It also allows you to cue units from their respective buildings while paying attention to other things such as macro workers or micro an attack force. This is especially useful for queueing up workers from your command center. It is incredible useful when across the map or away from your main base allowing for instant attention to any number of units and works just as well the other way allowing attention when troops reach a destination point. I cannot stress how important this skill is to work on. Practice against easy comps to get a hang of having hot keys if you don't use them and get better if you do. this can also apply to unit shortcuts, as important as the hot keys are.
