Yes, and yes
Let someone more knowledgeable than I hold those two factors into account. 
Seems to me you’d crush the fiberglass thus rendering it useless as an insulative material. I’d consider stacking fiberglass batts on top whatever I did with the vapor barrier.
Blown in insulation tends to settle over time, so I think batting is superior. I’d suggest that you can probably just punch holes in the existing paper and drastically reduce any possibility of a condensation problem, especially since you haven’t seen any problems w/ the existing insulation.
Since your main concern seems to be summer cooling you might consider better venting of the attic and/or a temp. controlled attic fan instead of adding insulation. If the house has eave vents you might also check to see if these have been blocked by the current insulation.