>It would seem to me, that since their phonetic inventory was wider
>than the 22 letter alphabet could fully accommodate, it would seem
>that they were the adopters of the alphabet.
The Hebrews almost certainly adopted and adapted the Phoenician
writing system, adding the matres lectionis: vocalic heh, yud, and
vav.
I think the evidence for a wider phonetic inventory is less clear than
other bits of information. We really don't know what Hebrew sounded
like 3,000 years ago.