#1
Can you solo with minor pentatonic over major chords? or do they have to be power or minor chords? thanks
#2
Yes, you can.

For example, we can look at Hey Joe, the Hendrix version. He uses E minor pentatonic over the chords. The chords are C, G, D, A, and E. That's 5 different major chords he's using one pentatonic scale over.
#4
General rule of thumb:

pentatonic minor works over both minor and major keys
pentatonic manjo works only over major keys


though like mentioned their are no cemented in rules about what you're allowed to do, if it sounds good do it.
#5
by pentatonic major do you mean the box pentatonic box pattern right below the minor pentatonic or are all the pntatonic box patters minor?