Jothar,
Loshon Hakodesh was last spoken as Klal Yisroel’s everyday language before the churban of Bayis Rishon, when Yidden were on a far far higher madreiga than us today. They were far more careful with their speech, what they said and where they said it. This has not been the case for about 3,000 years. Any of us are far far from being worthy to use Loshon Hakodesh as an everyday language, the menuval Ben-Yehuda not withstanding.
Btw your joke about the hoizen/heiser goes the other way than you implied. 1 – The Godol’s levaya was in Yiddish and 2 – the joke was on this poor guy who didn’t know the correct terminology.
Are you Jothar stripping Rav Cohen from his status as poisek? You agree that Rav Shteinman is a tzadik and Godol Hador. So let me ask you two questions: 1 – Vi shteit? 2 – Oib es shteit nisht, is er ois tzaddik?