Hi Paul,
This is something that is usually specific with Clients needs, but this is easier done when you are starting an implementation, of course. Shift everything to PAM may takes time, and depending on the team's background it can be a really hard task.
But, once you have an Action/Rule/Event (yes I invert it to show that the one that calls PAM is the Action) that triggers a SRF on PAM that call a Process, the sky is the limit, you only have to be creative.
What I usually do is, the way PAM+Catalog works best in my opinion, is Catalog controlling access to an offer (in the end, a form). Everything else I use PAM.
My two cents