This is a topic which would necessitate a re-write in HARP 2.0
Let's take it easy.
It should say:
The Maneuver Penalty from armor is applied to all skills MANEUVER ROLLS with Agility or Quickness as one of the modifying stats.
The Maneuver Penalty from armor does not affect basic DB gained from armor, shield or talents, as basic DB is not a maneuver. Instead, The Maneuver Penalty from armor modifies any DB gained from the Quickness stat bonus. However, this penalty cannot reduce the bonus gained from the Quickness stat below zero,
Even utilizing the character?s Armor Skill, a character cannot reduce the penalties (max/min or fitted/unfitted) for the armor worn below the value gained by the Armor Skill.
And then, describe what min, max, fitted or not penalties are
So:
1) Does the armor maneuver penalty affect DB?
Not basic DB, just the Quickness bonus.
2) If so, then that would be true for all four categories above, and not just MxMP, yes?
All penalties are treated the same way.
3) If not, then is the mention of DB in MxMP a typo, or is there something else going on there?
It's the key to understand 1, but it's not specific to MxMP, which is why we were many to fail to understand at start.
4) In RM, there?s something about a character?s strength bonus canceling out encumbrance or armor penalties, isn?t there? If so, is that relevant here?
No.
(IMC, we use special materials (metals) for armors to achieve this. Chain and Chain-Plate of this type are very very rare and Plate is nearly unknown of.)
Errata is OK.
Hope this helps.