So I noticed that if your villager is a master in a skill they don't have any advantages (besides the obvious eg master in research get more tech points) so i thought i would suggest some. . A master gets some pros and cons in all of the six skills.THESE PROS DO NOT STACK

Farming. A master in farming gets....
-Farming. Gets food quicker by 10%. Puts it in food bin 20% faster
-Building. Learns building 5% slower.
-Research. If is holding food as a research thingy they achieve 5% more tech points than normal
-Healing. Learns healing 10% faster
-Parenting. The persons kids will be farmers if a job is not chosen by you.
-Devotion. Before eating they will thank you (god) for the food and get some devotion skill and points.

Building. Master builders walk 20% faster.
-Farming. Collect food 5% quicker
-Building. Will exercise when you are off. 25% faster
-Research Learns research 20% slower
-Healing Learns healing 15% slower
-Parenting Kids will like to exercise (gain building)
-Devotion. Can walk near all heathens

Research
-Farming Picks food 5% slower/faster
-Building Learns building 15% slower and walks 5% when building
-Research Walks 10% faster when researching
-Healing Gains a little healing skill while researching (trainee)
-Parenting Kids will not learn building skill from school
-Devotion Learns devotion 15% faster but conforts heathens 20% slower

Healing.
-Farming Picks food 20% slower because they are checking if its safe to eat :P
-Building Does not get hurt while building
-Research Gets hurt slightly when researching
-Healing Kids and person live 20% slower
-Parenting Has a higher change 15% to get twins and 10 for trips
-Devotion Learns devotion 15% slower

Parenting All the pros/cons are kids learn the skill 1 - 10% faster

Devotion
-Farming Picks food 5% faster
-Building Is 10% slower while building but each trip counts as two normal trips
-Research Learns 10% faster/slower
-Healing Gets trainee in one shot
-Parenting kids will have extra devotion points
-Devotion Comforts them 5% faster

I hope you like this and take this to consideration. Maybe only do the pro/con of the skill the villager is master in.