What should I kill?

I need advice from the group. I live in a small sub in MI that has a
private 4 acre pond. I am the only person who fishes it. It has bass (a
couple in the 5 - 7 lb range), some yellow bullheads, a whole bunch of
bluegill, a couple small perch, and some good sized crappie. Yesterday, I
even caught a 6" pike. I also caught 4 doz bluegill and a 22 lb snapping
turtle.

Most of the bluegill are quite small. Very few are larger than my hand.

Should I cull the small bluegill from the pond? I seem to recall some
ancient wisdom that says this is a good approach to managing the fish
population. Would this help or hurt the bass population?

Secondly, should I kill the snappers should I catch any more of them? I
have no idea what snappers eat.