A vi K, it is not darchei ho’emori, it is Judaism, and denying it is Protestantism. The Torah itself says mezuza protects, and says not a word about having to know what’s in it. The gemara says that even a non-Jew is protected by a mezuza, and that “road warriors”, who rarely slept under their own roofs, would carry a mezuza with them and put it up in their hotel room each night, and this would protect them even though they were not fulfilling the mitzva.
The psak of the overwhelming majority of klal yisroel and of gedolei hamekubalim is that we *do* say machnisei rachamim, and we directly address the thirteen midos and ask them to intercede for us, and it is *not* a problem.
The Zohar says explicitly that we *should* ask the dead to intercede for us, and that it is *not* doresh el hameisim, because “meisim” refers to resha’im, even when they are alive, and not to tsadikim even if they happen to be dead.