I have started using Seam's integration with jBPM and I have found that it works pretty good. It solves the navigation problem.
Using jBPM page flow I would do something like:
Have the users start at some common page.
When a user clicks on a link to see the list of properties, run a decision. If the decision works out that the user has authority to modify the pages, then send him to a modify section. If the decision is that the user cannot modify pages, send him to the read only section.
jBPM works out really well for these situations. The decision is transparent to the user; the user just sees what he thinks he is supposed to see.
Cheers Matt, will give it a go and see how I get on!