_Get_ is indeed the auxiliary in passive constructions, but it tends to
be colloquial, not literary. As for _very much_ in the sentence "I get
paid very much for my work" [ha!], it seems to be a headless noun phrase,
a sort of short hand for _very much money_. Thus, _much_ is not a noun,
but a quantifier, or quantificational addjective (whatever terminology
you may use), and _very_ is very much the intensifying adverb we know and
love (sorry!). And, _very much_ is a retained object, given that the
active version of the sentence is ditransitive, with two objects: [My
employer] pays me very much for my work.