I'm working on a setting in which all humans have been genetically modified to have access to telekinesis ages ago, and it is now considered a normal thing. It works somewhat like a muscle in that the more you use it, the better you get at using it. It's upper limit, is that you can only impact an item of less than half your weight, less than your own body length away from you. On average, people can only lift between 5% and 10% of their body weight at half their body length away from them. This power cannot be directly used against living material, and the acceleration of an object can't be thrown with any more force with telekinesis than throwing it with muscle force instead. It is not physically strenuous to use telekinesis, but it is mentally strenuous when overused, although it's limits are similar to physical strength in that minor uses don't exhaust you, but using your power beyond your endurance level will leave you tired. Overusing this power way beyond your limit will result in the user passing out or falling asleep with maybe a slight headache when they wake up.
This is intended to be a background element that isn't directly important in the story, so I'm looking at finding out how to limit this power so that it isn't the main focus of the story. Now to the point, there are three primary areas where I'm curious as to how this would impact a society.
How would this impact a medieval society equivalent to our own middle ages?
How would this impact us if it were to happen in today's world?
How would this impact a more technologically developed society than our own?