My main panel is 200 amp max. I'm assuming that there are 100 amp per leg or side if that is true then in theory I could put in another dbl pole 100 amp breaker on the opposite side of the current dbl pole 100 amp breaker, and use the new one to run to my shed. And if this is still true I could then run two #3 wires from my new dbl pole 100 amp breaker in my main to the two legs in my box in the shed, and run everything else internally from there. Sounds too good to be true.
Everything in the picture is not in use except the lower right corner.(100 amp dbl pole breaker which goes to the box in the house)