besides the zohar, chazal are replete with stories of tzadikim davening on behalf of klal yisroel…by the churban beis hamikdash, the avos, moshe, etc…davened, and only rochel was answered. many such stories, and this is part of why some hold you can ask a tzadik by his kever to daven for you, but nowhere does it say that the tzadik himself answers and fulfills your requests…that would be a violation of the 13 ikkarim, as the rambam says you can only daven to Hashem.
and yes, a tzadik can accomplish more in shomayim…through his davening…oy, why do i have to explain this?
As it happens to be, that zohar is not pashut, because there are seforim which say that as tzadikim grow higher and higher in shomayim, they lose the ability to daven for people, because they see how what we consider to be suffering is ultimately for the best.
but I suppose some tzadikim, such as the avos, etc…, are on an even higher level, where they can see how it’s good but still feel the pain of regular people….this is just my own theory; i have no idea what goes on in shomayim.
and I’ll humor our friend a little more – what do you intend to take out from the sefer you linked to? it’s about moving meisim, the pain they might feel, which circumstances you can move them, when it might be pleasing to the meis, etc…
what does that have to do with their ability to help you directly or have absolute insight of what goes on in the world all the time?
absolutely nothing, of course. But it’s an interesting teshuvah regardless, so thanks for sharing!