First question, I don't know for sure.
About the strength, yes you'll need more if you're trying to play the same way. If you didn't set your guitar up after you put the heavier strings on, that could contribute to it feeling more difficult to play as the higher tension strings may pull the neck more and raise the action.
On a side note, heavier strings allow for slightly lower action because the arc they make when vibrating is a little smaller. If you ever get the chance to play some jazz-cat's guitar that's well we'll set up with super heavy strings, you'd be surprised how easily they play.