What is the significance of Aharon waving them?
Rashi: In the same way as an Asham Metzora is waved alive.
Why does the Torah mention Tenufah three times in this Parshah?
Rashi: Once regarding the Bnei Kehas
Because they carried the holy vessels.
Because they too, transported the curtains and the hooks, which were also Kodesh because they were visible in the Kodesh Kodshim.
Since they carried the planks, which were not Kodesh.