Are the following statements true? I've picked them up somewhere.

1) If villain is overbluffing a river spot, let's say he's a volatile fish, we should call all bluffcatchers.

2) If villain is underbluffing a river spot, let's say he's a nit with low postflop betting frequencies and nitty preflop stats, we should fold all bluffcatchers?

3) Follow-up question: How does fish making polarization errors, betting with weak/medium made hands affect this concept?