I have a 1/2 acre pond with the following fish population:

Bass: 5 (1/2 to 2 lbs)
Bluegill: 100 (all ages)
Channel Cats: 15 (1/2 to 6 lbs)
Flathead Cat: 1 (2 lbs)
Bullhead: 500 (more or less 3-5 inches)

I have just recently taken over the stocking of this pond and i want it to be a balanced fishery. Will the flathead eat the bullhead first? I am feeding the catfish. How big will that flathead get and how soon? When should i take him out or should I? Should i even have put him in there? I do not want him to eat the bluegill. Where should i go from here?