Re: amount of coals?
3 Kings I always used 2. Let the coals sit for about 10 mins before you start hitting it. Rotate them every few minutes around the bowl on opposite sides. Also try making a wind cover out of tinfoil, will help you manage the heat better.
When yo get a vortex, I tend to use 3 natural coals to start it, then take one off after the bowl is heated up.