I agree that the local vernacular can be used to great effect, as long as the translator has a good grasp of both languages. I further agree that oftentimes, it's a half-assed attempt, and therein lies the problem of the awkwardness and silliness of the translation. I have no idea how a Sanskrit dhāranī translates into Tibetan viz. its accuracy. I've heard the Lotus Sutra in Japanese, and was totally mesmerized by the meter and melody. Is it faithful to the original? Beats me!
And as I said, when using a language that is not one's mother tongue, I don't think that a horrible accent renders the mantra or dhāranī useless or unacceptable to the deities. At the risk of offending anyone, I call dogmatic b.s. on that one, as I mentioned. I think it goes to chapter 9 verse 26 of the Bhagavad Gita: "If one offers Me with love and devotion a leaf, a flower, fruit or water, I will accept it"
... i.e. it's the thought that counts (regarding the pronunciation, the translation should have some resemblance to the original
). Btw, I was also told by this person that the verse refers to offering a physical item, not a heartfelt devotion.
But I think I'm pontificating now.