From what I can tell, including everything written here, I don't see any NEED whatsoever for the Advanced Scuba Diver or Master Scuba Diver card. Those, in and of themselves, don't seem to get you anything. It's the specialties you have to take and the number of dives you have to log to get them that matter.
Kairoos, it seems to me that all you need to do is the Deep full specialty course. You'll have a card for that after you complete it, which you can show if a dive op asks. You may also need to log a certain number of dives to satisfy some dive ops. But, those wouldn't have to be any kind of training dives.
I've been looking at a night dive that requires prior night diving experience. If you were doing the same, you could also take the Night Diving specialty class, which should satisfy the requirement for that.
IOW, from what I've seen every dive that requires more than just OW requires something specific and if you have done the specialty courses for those specific things, it's not going to matter if you have an Advanced card or not. (though you still may need to have 25 or 50 logged dives)
Also, I just got back from the Caribbean. I told my dive op it was my very first diving since getting my OW card. And I told them I had already gotten my Computer Nitrox card. They took me to 85 - 89 feet on two different dives and they supplied me with Nitrox. And they NEVER looked at ANY of my C-cards or dive log. So, depending on where you go for vacation, I wouldn't worry too much about documentation issues preventing you from doing the dives you want to do. If it's in the U.S., I would expect dive ops to be sticklers - at least to some degree. Outside the U.S. - at least in places like the Caribbean - less so. After all, it's really all about liability and insurance, right? Other than an altruistic desire that a dive op MAY have to keep their customers from getting hurt, the only reason anyone checks documentation is to protect themselves from getting sued, right?
First- I can tell you some dive boats in Europe, Central and South America and of course -stateside- including northeast wreck boats- will require an advanced diving card (AOW, MSD) or proof of significant depth logging before taking you to many of the deeper sites where the best wrecks are.
Second, anyone who dives today should be doing both Oxygen and CO testing/analyzing for their fills and filling out a Nitrox log at the shop. That record is both for your and the dive ops benefit - and if you "skip" that part you are only endangering yourself... Or leaving your family without a vital record in the event of an issue on your dive.
In filling out the fill log- you need to enter or write your Nitrox/EAN cert number...
Third, I wouldn't use one shop as a representative sample for basing a norm on...
But hey - it's your call...