I not looking for exact numbers per say, but some indication on whether morale is scaled like, say, damroll, where +2 is decent, and +5 or +6 is basically max on an individual piece and will put damroll as high as it can reasonably get, or if it is on a scale more akin to saves, where -5 is basically the minimum useful value, and -20 from a piece is within reason.

Also, for +morale items, does this adjust the base value and push you ever higher from natural things, or because morale sort of tends toward the middle is it basically a temporary boost that doesn't have much overall effect?