Besalel is completely correct. I was going to write that I agree with him, but then I dug deeper into the matter and determined that I agree with him because he is correct.
The story with R’ Nachum as well illustrates the fallacy of this mode of avodah. Would you dance at the grave of a relative? Under certain circumstances, sure. For example, if the relative spent his life trying to find a cure for cancer, and some time after he died, a process he discovered is perfected and turns out to be effective. I would absolutely celebrate at his grave.
The Bais Hamikdash was destroyed because of sinas chinam. It is perfectly valid avodah to dance at the kosel as an expression of achdus. If R’ Nochum doesn’t want to dance he doesn’t have to. I assure you, R’ Nachman will not give him lomdus tips.
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