The Muzinka/broom dance was bought about by the early not-frum yiddishists and is not a minhag at all.Due to being unaware of its roots and having a yiddishe name it has become more commonplace over the years. Many people are not aware of this.
Regarding using brooms during the dance around the parents:
As more then one Gadol I heard basically put it(paraphrasing direct conversations): A Yiddishe mother and father should never, even after marriage of a child mimic sweeping kids out of the house or to give a sign that chasvishalom their jobs are done. Davka especially as they send them off they should always show signs of open homes to the new couple where they could come for advice and IM Yirtze Hashem show that they keep a place where they and their future families are welcome.
A Rosh Yeshiva (now in the Olam Haemes) was once so upset after witnessing people dancing with the brooms by a wedding that he spoke out against the practice publicly as he realized people were just totally unaware of where the broom dance originated and what it signifies .
As one older Rav once told me.”It is a tremendous accomplishment to see all children married and the parents (even with a possible dance around them)should be acknowledged but this could be done without the broom.”
May we have only Simchas in Klal Yisroel