Checking if user needs to verify before allowing posting (through API)

The call you'll need is on this page: http://community.lithium.com/t5/Community-API/bd-p/developers-rest-api?leaf-id=Settings.name.name#Settings.name.name

The name of the setting you're trying to check is: config.email_confirmation_required

You can also see all settings for a user by paging through a call to /users/id/[id]/settings

Hope that helps!