You have made GreYt progress with Stormy. It is always wonderful to hear from those that have put so much love and patience into rehabilitating one of these Greys or other Parrots. :-)
You wrote" "At times (he hasnt done this for a few months now) he would just flip out. Screaming, flapping all over either inside his cage, on top of his cage, or even on the floor. I dont want him to have to live in fear, or have these explosions of psychosis."
Something has to be triggering this type of behaviour. Something your wearing that you don't normally, sounds not normal etc. You will really need to be paying close attention to details with all your senses to figure it out.
The other possibility, is there is an underlying health issue that truly is causing a type of psychosis or similar mental change. Has he had a complete blood work up and exam?