New to the board and have been reading several threads from this board but couldn't really find an answer to my questions.

The pond is a small pond. 1/2-2/3acre roughly and 12ft deep. The previous owner stocked it with blue cats, largemouth and bluegill 20 years ago. Seems to have maintained it well until the last year when the intake system broke, didn't fill with fresh water for 8 months and basically became a large puddle. I fixed the intake, got the pond to refill and to my surprise there is fish left. Very big catfish, stunted bass and what seems to be a very small bream population. The catfish seem to be up to 15lbs and I've been told to remove them from the pond but for obviously I hate to lose big fish to took years to grow. Not sure how many there are but there's at least 5 that are 10lbs plus (seen that many at one time while feeding them). Have not seen any smaller.

So with that said here are some questions I have and sorry for being the noob:

1:) will blue cats reproduce in a small pond?
2.) do I need to remove the big cats so the bluegill pop can replenish?
3.) should I thin out the largemouth as well?
4.) if I restocked the bluegill am I just adding temporary forage that won't reproduce?

I'm a bream and bass man. The cats are fun to catch and feed but not my main thing. I'm a long time largemouth fisherman but brand new pond owner/manager.

Any advice or experienced opinions would be appreciated. Thank you

Attaching pictures and a video hopefully