Industrial training (schools)
historically schools have been a place for industrial training for the average person to gain manual skills. I propose a school that allows you to refund some skill points to re-train in to a new profession. say you where a cook and would now like to be a smelter. Like in a real world situation you would know loose all of your previous training but you would no longer be an expert. for example, if you have level 5 in culinary arts and you re-train, you go back to level 2 and receive the skill points that were used to level from level 2 to level 5.
Another benefit of a school is, for people that have not had the best diets and not received many skills points through out their time, they can train some up in their selected profession. For example, at the school table (we will call it, i envision something like the town hall but with more books/shelves) you can skill up masonry but creating stone products at the school table (items crafted at the Quarry), they are consumed by the table and grant you a skill/s based on the materials used and products crafted.
Schooling could be a branch of the civics tree and allow people that have maxed out a profession to create and train others for a fee (perfect with the currency system). This would be the limitation so that people that already have received a lot of skill points will not be able to take advantage and gain an exponential amount of skill points.
So in short, only those that have level 5 in a specific skill can make a school and allow others to train at, whether for a fee or for free