Well, I agree with pretty much everything you wrote here ... almost everything.
But I do have to disagree on one thing: The older I get, the more sensitive my nose is getting! Strange as that may sound, but my "honker" seems to have become extremely sensitive in the last few years. I'm 63, never smoked and my "honker" picks up smells and odors that most others never notice or can't smell. For example, when we pulled up to the campsite we are currently at, I stepped out of the truck, walked past the fire pit and smelled cigarettes. (yes,.... really!)...I looked down and sure enough, a dozen or more cigarette butts. My nose drive my wife nuts.
Now, about the rest of your dissertation? I think, pretty much, all you said is correct. However, I do disagree that chemicals are necessary. Why? Well, I don't have an odor problem from my black tank and here's why.
I dump often and flush the thing out A LOT. I back-flush from my grey tank and then will also follow up with the black tank flusher. I have the advantage to dump at home, and it all goes down my septic tank. Chemical are not an option, unless it is household chemicals like laundry soap and bleach for laundry or dishwashing liquid products.
If you consider dishwash liquid a "chemical" (which, in a way it really is), then I do use chemicals.
But I have found, dumping the tank, adding a bit of water, driving to the next destination and letting the contents slosh around, and then dump at the next destination, flush the tank with lots and lots of water, until the contents come out clear and all the globs of stuff stop plopping out, I don't have problems with smells inside the trailer.
Now, when dumping, I agree, it stinks! But draining, back flushing, and tank rinser flushing keeps everything that can grow "bacteria" from finding a permanent resting place on the sides or roof of the tank. That's the secret! Flush the tank. If nothing is in it for bacteria to grow on, then you'll not have smells.
Now... I've noticed my grey tank ... when flushing it, not the shower, but the kitchen sink grey tank ... now that one REALLY stinks when draining it! It smells bad. Every now and then I'll just pour a bottle of bleach down the drain, let the water run about 3 minutes and go for a good drive! That will clean it up pretty good, as long as it's flushed from the chlorine!