I am using the suffix -hood as both base and suffix to derive poetical meaning in an interplay of the words "...child and adult hood." Though this may offend the ear of the modern day reader, I believe its earlier usage was separate from its base, and I'm not so sure it would, on the surface, be much of a technical blunder anyway. What do you think?
Timmy had a miserable child and adult hood.
This sentence doesn't parse well because there the reader is unlikely to notice that "hood" is intended to change "child" and "adult" into "childhood" and "adulthood". At the very least, I would recommend using a hyphen:
Timmy had a miserable child- and adulthood.
(?) Timmy had a miserable child- and adult-hood.
(Whether you use a hyphen in "adulthood" is debatable. Adulthood is nearly always written without one but the meaning would be clear if you included it for poetic or stylistic reasons.)
This usage is uncommon but is considered correct depending on the words involved. You can read more about it at Can a hyphen be used without anything on the right side? That question's example:
[...] in early parts of this century when it was the most user- and hardware-friendly Linux operating system available [...]
Whether "-hood" could be used in this manner is less clear but, for the sake of poetry, I would call it good enough.
You might be right that the element of wordformation -hood as in childhood was in earliest time a word of its own as suffixes don't fall from the sky. But no one can tell for sure was that word was. Etymonline presents a theory of a word meaning "shining". Not very convincing and the semantic connection is not plausible. I would guess -hood is connected with Latin aetas/aetatis - the stem aet- might give the German suffix -heit ( h + eit) as in German Kindheit (childhood) and the logic of this formation would be clear. Aetas can mean age of a person and "Kind + age" would mean "the time when one is a child". And I think it is not difficult to see that the German suffix -heit and the English suffix -hood are related.