Thanks for doing that testing. :-) I have now connected Phoebe and Edward. When the two parents of a person are already shown as married, and one of the parents is PPP, the PPP setting should not prevent the child from being connected to the non-PPP parent.
As for your not being able to connect Phoebe and Edward, that's one of kinds of edits that PPP is designed to restrict. Family member connections to PPP profiles can only be edited by a Project Leader, Project Coordinator, or a Profile Manager of the PPP profile. I do wish that more members would request profile manager status on the profiles of the New Netherland ancestors (PPP or not) who they are researching.