Sorry I don’t get the reference/joke about the “a touch of madness” trait in the plumber lifepath, can someone share something ? 
Working with lead pipes eventually gives you lead poisoning - then you go crazy*. Thus the trait.
http://en.wikipedia.org/wiki/Lead_poisoning
*Amidst a host of other exciting side effects from chronic lead exposure.
~Gary
Yah, heavy metal poisoning also lead to Milliners going nuts too. Hence Mad-Hatter.
This is one reason why I love BW 
I agree, thats awesome!