I read all the story, but not the full 27 pages of response, but wanted to add about my trip there.
I am a MI with more than 5000 dives and went to Belize for a holiday with a few days diving with a friend of mine. She is not as experienced but a good diver.
We went to the blue hole on the same type of daytrip, 3 dives with the island lunch.
My experience was
Open water divers with NO computer were taken on the dive.
The DM didnt really show any concern. I told my friend to stay close, she has a deep cert and I lent her my spare computer.
We stayed at 40m max and shallowed up so as not to go in deco, many others did not.
We did a deep stop and extended safety stop, even though we were being told to get up by the DM.
Our surface interval to the next dive was short, maybe not even 1 hour, as they wanted that dive before the island lunch stop.
I was given the same tank for my last dive as the Blue hole one, and when I questioned it was told it's enough air for you.
Ok maybe it was, I dont use much, but I was a paying customer not a guide and should have had 3 full tanks.
We were given rum punch on the way back, again to keep everyone quiet on the 3 hour journey and increase tips. I didnt drink it.
I found the operator not interested in safety, customer service or operating a business I would consider diving with again.
The nature of the Blue hole means everyone has heard of it and wants to dive there, this does not mean new, inexperienced and unequipped divers should go there. I dont think it is just one dive center that does this it is almost certainly all of them.
I hope you have recovered and learnt a lot from your experience of what NOT to do in future.