1. If an initial population in an excited state is not replenished , and the probability of emission from the excited state is proportional to the amount of nuclei in this state, then we expect the number of emission events per unit to decrease exponentially.
2.Supposedly 1-3 is in line with the nuclear spin and explained in the video was that the spatial distribution of gamma rays was highest along the spin-axis and lowest perpendicular ,in this case , 1-2.