I believe the answer would be to carefully observe the extremities for circulation.
A: the cast needs to dry out, but you also want to decrease any swelling. So elevate the extremity and evenly dry the cast by turning it every 2 hours.
B: general alignment is important, you want it to heal properly
C: Compartment syndrome (emergency) can be a complication, and it is extremely important to monitor. Check the 6 Ps (pain that is not relieved, paresthesia, pallor, pulselessness, poikilothermia, paralysis)
D: you want to handle the casts using the palms of your hands, not the finger tips.