Will not have to admit. The term has nothing to do with rate of fire. Normally purchased weapons, assault or not, are semi automatic. Rate of fire only applies to automatic weapons.
Right, even then the rate of fire is only relevant as to say it was a single pull for multiple projectiles vs a pull for each round. If you have the money to pay the $200 tax stamp, undergo the background check, and can find a pre 1986 minigun, you can shoot upwards of 6k rpm. Some states may have prohibitions on it, but again, those are being contested in courts and I suspect post BRUEN they're not going to hold up to muster.