> The meaning of "good" from "be" .... is barely sensical,
Yet isn't this actually attested in Sanskrit where Sati (literally "she who
is") means a good woman?
The meaning "real, existent" survives: tatha: sati = this being so
but the meaning "good" is very common for all genders, and it gives one of
the words for "sage" or "good man".
So perhaps a similar shift in meaning in PIE is not so improbable?
Peter