yeah, that'll work..
"The FAA in the US recently announced the mandatory registration of all drones over 250 grams"
Terrorist1 - Okay, let's fly this baby to the target and drop the ricin...
Terrorist2 - Have you registered this drone?
Terrorist1 - No..
Terrorist2 - You idiot, it's got to be registered else it's breaking the law. Cancel the attack!
Along with all the other thoughts/plans, it'll only impact honest, law abiding citizens. Those bent on action will always find a way, the cat is well and truly out of the bag regarding how to build a drone. The hardware and software required are widely available and/or easy to build if you know what you're doing.
Lifting limit - Fit bigger motors
GPS walling - replace guidance system with one that doesn't.
Radio jamming - use a preprogrammed route
About the only thing that *could* stop a drone strike would be radio jamming combined with gps jamming, but then the target would get hit by half a dozen very confused self driving cars.