While it's not specified in XEP-0060 that non-owners should be able to access the subscriber list, I'd say it's perfectly reasonable for a given pubsub service implementation to allow you to override access control rules.
Unfortunately I don't know Openfire enough to know whether this is possible there.
Update: On re-reading your question I realise you might be trying to use a pubsub node as a pseudo-MUC room. The problem with this is that you will not receive notification when the subscriber list changes (i.e. someone joining or leaving). You will also not be able to add extended information the same way you can with normal presence stanzas.
For this reason I don't recommend this approach (given the little I know of what you are trying to do).