Do you love big bluegill?
Carp are not a predator - they're technically omnivorous, but they eat little to no fish; they're bottom feeders, and the animals they eat are mainly invertebrates. And catfish, if you mean channel cats, while certainly predators, don't do nearly as good of a job controlling bluegill as largemouth do.
I went to the California website for Lake Irvine. I fished the lake once when I lived in L.A., and remember being told that high numbers of trout are stocked into it; the website says 5,000 pounds per week, which is a heck of a lot of trout for one lake, even a good-sized one. While trout certainly are predators, unlike largemouth they also eat a lot of the same foods - aquatic invertebrates, for instance - that bluegill do. I would venture that the heavy competition for food that the bluegill face from the thousands upon thousands of weekly-stocked trout is the reason the bluegill aren't as big as some other SoCal lakes. And, one of the species listed on the website is carp, so that's another species directly competing with the bluegill for food.
Good to know a few facts about carps. The carps in Lake Perris are a mix breed. Some are predatory opportunists, where as other merely enjoy anything they can get to. When I metered the spawning areas of the panfishes, I always see carps and cats linger within the area. A shared habitat or a predation in motion, I can't say without a camcorder rolling the footage. The water is so stained here that you can't see beyond 3ft below surface. However, what I witnessed in the shallow areas got me baffled. Carps chasing baitfishes along the sandbed, or carps leaped out of the water, hammering floating bugs on the surface of the water, including my flies, like basses. A few who caught carps also found small 2" gills in their bellies. Just scratching my head at what are these carps true diet is.
Irvine is over estimated on their stock trouts planting. 5,000 per week is way over indulging our eyes and ears with news. More like 2,500 per month. If we're lucky, 3,500. Holdover trouts that can get into the double digits since not many of us drive down to Irvine on a constant basis, and they have quite a huge area to hide form shoreline anglers. People who live in the Orange County areas like to hit the salt water over the fresh water for fishing activities, mainly piers and surf fishing. Trouts in Irvine is known for their voracious appetites for baitfishes and gills. Large trouts will hunt for baby gills at their spawning beds near the eastern shallow area, as well as the southern shore were vegetation can get dense. It's the best fishing ground to get lucky with the double digit trouts.
However, very rare does Irvine Lake get monitored like Lake Perris. The reason why is Lake Perris is constantly reporting in fish species being captured, and the plenty of angling volunteers willing to share their time to help out DFG with their tasks, and learn a few things in the process. I'm definitely no expert on fishery management, but man, a few things I found from fishing experience just baffle me. Thanks to this forum, I learn more about the panfish's capacity to reach new heights every day.
Definitely want to have a harvest plan of some sort in place and you got some great suggestions here. Depending on how compliant the allowed anglers are, you should be able to keep it a very good fishery.