Hi, like I stated in another response, the school feature is already on the to-do-list to receive big changes in the next update, and I will be addressing the literature subject as well.
Farms, plantations and mines do not show "Increase capacity" because the first building does not increase it
The mining x5 modifier will stay, even later in the game, but there are other reasons to visit earlier depths (this starts being a thing at around 50m)