transitivity, locative prefixes & the pronomin. argument hypothesis.

[Pamela Munro]

Speaking as a lurker who knows quite a bit about Siouan languages and
this typology, my answers would be

1. Yes, it is the direct object (atypical for a DO semantically, but a
DO).

2. No, it is absolutely not a DO.
I would not call it a voice marker either as I understand the term. For
the comparable morpheme in Lakhota and other languages like this I know
of, I would consider it essentially a detransitivizer. But maybe there
are subtleties in Osage I'm not familiar with.

Pam