Metrodriver, I think it is sort of sad that all your examples of minhag are that of chitzonius, and sad that some of our fundamentalist brothers equate a mussar from kesuvim to a d’oraisa.
There is a tshuva in Igros Moshe ztkl, about someone from chassidic ancestors, but with frumkeit skipping the genration before his, i.e., a BT aware that his grandparents or before them were chassidim. Reb Moshe ztkl paskened he should adopt nusach Ashkenaz. I am such a case, and count myself fortunate to have learned by a RY who himself had many unique positions in finely detailed halacha, but very few minhagim.