the word brahman literally means to be.No. Brahman isn't a being, it isn't a thing, it doesn't have characteristics, it's not God though it's oversimplified and erroneously equated with God. There's nothing "in vain" or "having no purpose" in saying the Mahāvākyas. They're statements of belief and philosophy.
Brahma (ब्रह्म) (nominative singular), brahman (ब्रह्मन्) (stem) (neuter[23] gender) from root bṛh-, means "to be or make firm, strong, solid, expand, promote"
the name in judaism is basically a verb meaning to be also. it comes from the word hayah.
thank you for sharing that the name is not taken "in vain" or "having no purpose". i'm also aware that its understood that namaste recognizes that sacredness within others.