Son of a gun*, I read through the most of the thread and all of the OP's 13 page manifesto. And dang* me, if there aren't some good points being made. But what the heck*, I like to swear and in certain contexts I do it quite a bit. It can be freakin* beautiful self-expression
For me, there is a large distinction between P&V (profanity and vulgarity, per the OP) and blasphemy.
The former is a celebration of the earthy, the bodily, the primal - that lends itself to a language of the emphatic, the funny, and in many instances the intimate, or clubby. Which is a big part of life.
Blasphemy, for me at least, is very much the erosion of the sacred and the reverent that the OP writes about. I strive (and occasionally struggle) to avoid it as I'm uncomforatable with anything that mocks, or diminishes, the Creator.
I write a lot of emails. Just today, in various emails to clients I used the following words: desuetude, capricious, gestalt, folderol and many other fancy-fine utterances. Why? Because I like words, and the extraordinary gamut of subtlety they can convey. But honestly, those words? There is really only one way to mentally recite them - a little bit pretentious and a lot stilted Whereas the word '****' is all about the inflection, the tone, and the emotional underpinning. It can be a declamatory bomb or a slow rumination; a purr of possibility or an expectoration of surprise. It provides an almost limitless shorthand of decription.
A last question for the OP; what about the * words in my first paragraph? They're generally considered inocuous and acceptble in almost any conversation but, aren't they just cursing lite? They are all derived from vulgar/profane words and, as a direct stand in for these words there is no reason for them not to be equally offensive, or unnecessary. I think in the end it's the semantics of phonemes and values we assign. Which is mostly arbitrary.
Finally, I just want to thank whoever resurrected this thread since, as a relatively recent FNG, I might have otherwise missed this edifying content that perfectly encaspulates the reasons I joined Rokslide.