I'm sort of planning a semi-fictional aquarium, but I want your thoughts on what the animals would need in real life

nearshore coastal waters and offshore pelagic waters ig

Also, why other animals will be in the tank:
they aren't great whites favored prey. Just some small fish and small sharks. Just stuff that is not too appealing to great whites. I'll find some animals that live off Dangerous Reef and a list is coming soon!

Ok

can u give me some possible modifications to my tank

Ok I'll think of one..... Maybe some hammerhead sharks?

btw speaking of tankmates, heres the list
Smooth stingray, black bream, callop, gummy sharks, port jackson sharks, leafy sea dragons, snappers, striped bream, wobegong?, necklace carpet shark, Australian swellshark, and some others. If I notice any other species I'll comment on this list and add some more.

No, not tankmates. I'll research that myself. I mean stuff like enrichment, visitor amenities, stuff like that.

I'll give my tank specifics
Gallons: 3 million
Depth: 30 feet
Temperature: 70 F
Area representation: Neptune Islands and Dangerous Reef, Australia
Enrichment: Seal decoy, edible fish pinata made of pigskin
Feeding: Seafood smoothie, whole tuna, whole horse, whole pig
Other animals: Yes, I have an explanation for this
Visitor amenities: Underwater tunnel, restaurant, above water view
All the exhibits will be indoors btw