Question 5.  A few terms I looked up

 Brethren of the Common Life:  An association founded in the 14th century that was focused increasing Christian deviation.  Started by G Groote, he embraced a simpler life largely guided by the love of god.

Lay Piety:  As I understand, lay in this context relates to the lay people or the common people.  Piety is the devotion to god or a reverence for god.  The  common persons devotion to god.