You can change various of game constants by change their values from mod script.
Most of them located at fv.core.config table. For instance, you can change teenager age:
fv.core.config.citizenTeenagerAgeStart = 2
Some objects such as buildings have their own configs. You can alter these values same way:
fv.core.Apiary.config.buildTime = 700
It is good practice to change only those values that really have changed instead of redefine entire config for best compatibility with other mods.
Read more about available config's parameters: