As far as not doing photography inside places that charge for the privilege I'm with you philosophically. It's a practice I find very annoying in that it's essentially a way of double-dipping on the visitor, because after all, how many tourists and travelers don't walk in with some sort of camera at the ready?
As for the worry, no, it's not a big deal, but like everything it's simply handy to have a reasonable idea of what to expect.With all the museums, galleries and whatever that my wife wants to visit the extra for photographic gear could well add up to a couple of hundred or so if they charge each of us for our respective equipment - something to factor in. At least I can go in now essentially expecting it, rather than cursing and muttering and feeling like I'm being screwed!
Finally, there are answers and there answers. When people ask a specific question they want a specific answer. Unfortunately, and it applies to just about any forum you care to name, they always attract a select few who like to lurk and take a proprietary attitude, like it's their private little club where they can pal about and dispense their 'wisdom' in the most patronizing terms, frequently by offering up sweeping generalizations that have little to do with the subject matter at hand - the questions simply provide an appropriate platform for the resident expert to leap on their soapbox and wax rhapsodic to the supplicant silly enough to pose the question. Forums for the arts are appalling for it, not least photography. The amount of utterly pretentious and delusional people you come across on sites like that are staggering.
Example from here? I have been perusing countless pages on various sites, gone from one travel site to another, sites for tobacco aficionados, etc, trying to nail down a specific plantation in Vinales that would be appropriate in regard to my wife's physical limitations. With few exceptions the information offered up has been generalized material revolving around simply turning up and wandering the fields at random either by foot or on horseback, neither of which really seemed suitable for my wife. So I asked a very specific question, and what do I get in return? 'Just wander the fields at random or go on horseback'. Yep, really helpful.
I touched on the matter of the costs for photography, and I receive a treatise on how much to budget for visiting a third world country (never mind I've been to about a hundred of them in my time, some that make Cuba look like an economic and political paradise) and the matter of getting a particular credit card. Gee, really? The only relatively unique set of circumstances Cuba has are it's double currency, the penalty on the American dollar, and the issues with using American-issued credit cards there, though in all honesty there are many countries in the world where CC cards and ATM's might as well be in use on the planet Mars as far as the general population is concerned. I had in fact, all on my little lonesome, come across references to Stonegate some time ago, but I guess like everything else I should have mentioned it. In essence it seems at times that the only way you can get a straight and basic answer that cuts through all the rubbish and preening is to preface the question with a 10 page bio that essentially screams "Just answer the damn question and spare me the rest!'. It's one of the chief reasons that, despite all my years of extensive travel, I very rarely hang about sites like this to offer any advice or help because it simply gets wearying dealing with the other crap - the territoriality, the proprietary and patronizing attitudes, and the overt travel snobbery underpinning most of the behaviour and assumptions of ignorance. Go to a forum on Greece (my family is of Greek background even though I'm from Australia) and I guarantee you that 99% of the people providing the answers aren't Greeks, but all the 'Grecophiles' who've been to tourist horde islands like Mykonos and Santorini and think they know it all.
Thanks and over and out!
PS - and no, I'm not lumping you in with the people I described. From what I've seen on this forum over the last month or so of quiet research you're unfailingly polite, to the point, and very helpful. The pity is that more of the resident experts aren't like that.