Mdd, i think the shu”a harav was written with ruach hakodesh the same way i believe every gadol in every generation is guided by ruach hakodesh, because that’s what chazal say in numerous places, like in gittin(daf…5?) with rebbe evyasar.
As for changes in psak, following what he said in the siddur makes sense, and poskim change their shitos all the time – my issue is with what was said that chabad(or rather, this poster) can ignore a halacha in shu”a harav just because it was written earlier in the baal hatanya’s life, without him paskening differently. It was the posters own opinion(and perhaps their rabbi) that we in our time can decide what psakim to follow and what not to, based on our understanding of chasidus.
I don’t see how there’s verbal abuse in anything i wrote, but if you’re offended, it’s probably best not to be on here, or to engage in discussions with anyone outside of crown heights. I simply raised objections to what was said here based on clear sources and reasoning; if that is “abuse,” i really don’t know what to tell you.