Minion PR (in General)

I've been searching the forums for a description, definition and discussion of mpr, and I can't find it. Could someone point it to me? I kind of 'think' i know what mpr is, but not really. Questions that i would like answered are:
What is MPR?
How is MPR calculated and what affects it's level?
Are there things that can increase or decrease MPR?
How does tattoo level factor into MPR, if at all?
What's the difference between MPR and PR?
Is PR simply MPR with tattoo level factored into it?
Does MPR affect gains and BA cost?
What is the best measure of a strategy, score:PR or score:MPR?

I know some of these questions are redundant, but any help would be appreciated.

MPR is the same thing as PR on CB1 (to my knowledge)
as on Cb1, Training and untraining affect your MPR
tattoo's do not affect MPR
MPR is just trained XP, PR is MPR+tattoo added PR
BA cost is based on MPR
i believe that score is the best measure of a strategy

Minion power is the power your character would have if they unequipped their tattoo.
Any experience you train affects its level.
Thus, Untraining and retraining stats will decrease MPR :) Fighting will increase it.
Tattoos don't factor into MPR, because it's minion power.
Minion power does not count your tattoo power.
Yes.
No, power is used for fight gains (rewards) and BA cost. I don't know about BA rate, though (as testing would be both difficult and masochistic), but I suspect that's power, too.
Score:PR, because that's what is used to determine rewards. Also, because only %70 of tattoos' power is counted in the power stat, it makes sense to use a tattoo.

BA regen rate is based on MPR not PR.