Eric - your site looks quite impressive for a first site built by an OpenACS newbie!
One problem I noticed, though - the "edit this page" link shows up for me even though I'm not logged in. I doubt you want random people editing your home page??? :)
Looks to me as though your OpenACS permissions on that page are too permissive.
You are correct about the datamodel, if you didn't change the code in packages/foo/sql/oracle or postgresql then you didn't change the datamodel. And I would assume you'd know if you had.