Let's pause on the first one, because that's exactly what I want to address.
Is a high sustained rate of fire for a semi-automatic not somewhat of a contradictory statement considering that the rate of fire of a semi-automatic is controlled by the shooter and how fast they can pull the trigger? If it's a fully automatic, 100% you pull the trigger and rounds go off as fast as the firearm can cycle, recoil and put the next round down range. However, a semi-automatic's rate of fire is completely controlled by the shooter and has nothing to do with the firearm, unless you want to get into the technical aspects of trigger pressure and so on, which are not even part of this discussion.