Clearly, Cayman is notoriously expensive. It is what it is and if you didn't know that, your didn't look very hard. As the saying goes "The only thing that gets to Cayman without a ship or plane, is gossip". From your report, you're not really looking for diving. You want restaurants, and nightly entertainment. You didn't say a thing about shore diving, which is what any diver would be doing while you were out looking for parties at the pool. If you want to drink, overpay for mediocre food and smoke counterfeit Cohibas there are much cheaper places to do it than Cayman.
Some of us who like Cobalt Coast, like it because diving is available 24/7. That's what we go to a dive resort for. If you want long dives, feel free to make 2-3 hour forays right out front where you can find anything from hardpan to deep wall. On the hardpan there are dozens of species of gobies and blennies, many quite beautiful and rare. There are octopus, nudibanch and sea-spiders and who know what else passing through. On the wall you never know what you will see. There is no charge for a shore dive no matter how many you make. Ka-Ching.
For the cost of a polite request (Ka-Ching), you get a ride down to Lighthouse point where there is magnificent wall diving both mini and deep. The pinnacles across the sand are incredibly beautiful. If you can't do the wall on your own power (most people can't) you can rent a scooter to get you out there. On the hundred yard swim (from the miniwall) across the 70 foot sand you can stop off at the haystacks and or/spot eagle rays passing through. With your gas consumption, the wall should be no problem for you. 200 yards from shore and 100 feet down the isolation and solitude of the place makes a majestic and lasting impression.
I agree that the CC menu is limited somewhat, but since you haven't been to Cayman before you might not know that lunch for two at McD's will set you back $30; you can't go out for dinner anyplace nice for less than $100/couple and the food will be mediocre. The rate for the meal plan is very reasonable and completely avoids the horrible expense and disappointment of "dining out" GC. I'm sure a bunch of people will jump up and declare how wonderful the food is at this place or that. Good for you! When I want gourmet food, I make it myself and have it anytime I want. When I go to Cayman, I go to dive. The meal plan at Cobalt Coast is quite generous with unlimited buffet breakfast full menu lunch and three course dinner. All of the food is well prepared and there is something to suit most tastes.
Mandatory one hour dive limit on two-tank boat dives? Your dive count seems dubious or you're indulging in braggadocio. Given the logistics of a 2-tank dive boat trip, one hour is near the upper limit of what is possible at any operation I have ever dived. The boat (any boat) has to return (there are other guests aboard besides you) at some reasonable appointed time. People have scheduled tours or other activities and the boat has to be re-supplied for the next trip tanks unloaded, tanks re-loaded. Then there are air divers on the boats who need a super long surface interval before the second dive. The fact is, many operators on Cayman won't give you an hour, and will cut you off at as little as 45 minutes. Anyway, the time standard depends on the divers and how they use their time and manage their depth. All Nitrox divers is different from a boatload of air, as is a boat of experienced (known to the the DMs) divers. The "hour" is pretty elastic depending on how prepared you are. I've seen divers that take a half hour to get in the water after the briefing is done, getting in immediately, and out before the last of them, nobody cares if your dive runs 75-80; as long as you don't throw on a silly SI demand to make everyone else pay for it.
Dive-tech gets an A+ from most experienced divers specifically for leaving you to your own devices, time and schedule; something precious hard to come by in GC, where typical operators herd you around like sheep and dictate your profiles.
You mentioned all the Ka-chings with a distinctly derogatory tone, but failed to mention that the costs are equivalent at every resort. Kittewake cost hundreds of thousands to put down and is the cleanest best-prepared wrecks I have ever seen. Interior spaces are all accessible and free of debris. You have to buy a tag to dive it because the tags go to recouping the cost of putting it there. I'm not a big fan of wrecks, especially new ones, but I was entranced by the available light deep inside (there are multiple ways in and out of everywhere).
A 2-tank boat dive here in SoFla is $65 before adding tanks so the prices you mention are not at all extraordinary. The Lionfish killing dive you described includes instruction on how to clean and prepare the fish, as well as professional preparation and tasting of the harvest in several ways from ceviche to saute. The extra dives are completely optional and offered as a service to those who want it. I don't know why but everyone wants to go to stingray city. Lots of people are afraid to night dive on their own so the organized dive to Doc Paulson is on their behalf. You're depiction of these services is pretty mean-spirited and undeservedly critical. Yes, "I get the idea", as you say...you think everything should be free.
I'm not sure why you had the problem with the rooms, but if you want separate rooms, make separate bookings. Dora and Ari have are among the most gracious hosts I have ever had at any resort. They have gone out of their way to accommodate at every turn. Dora is the picture of politeness, so either you caught her on really bad day, or you somehow managed to piss her off (that takes some doing, BTW). I'm amused that you "ordered" rooms. Did you expect them built to your specifications? (c:. They have what they have and they ain't got no more. More than likely, you were told what they had available and misunderstood, or believed you could demand something else on arrival. Their rooms and layout are on the web along with pictures. I'm not a fan of the A/C situation either, but I understand that with the cost of electricity on Cayman individual thermostats is a license to bankrupt the house. Its not big enough for a chilled-water system that runs all the time, so the temp is set where its set, and that's that. The only time I found it uncomfortably warm is after rushing around and it always seems quite pleasant at night which is the only time I really care.
For people who want to dive, CC/DT is a great way to dive Cayman. Only the CA IV can surpass it. Diving Cayman well, is an art. Its not as easy as falling off a boat, and if you don't know what you're looking for or looking at you might not care for it. Cayman Blue is a distinct color and it exists only on the vertiginous walls there. Wall-flying there is like no other place (a thing unto itself) and the walls are where the actions is. Whether it is eagle rays, a rare Great Hammer or just watching the spectacle of life and death, the pinnacles, points and buttresses are where it all happens. Generally, the wall is within swimming distance of any of the "shallow" 2nd sites.