Hi David
1. Can there be user management synchronization setup between the Portal DB and external IdP's DB?
his is not possible as far as i know if you setup a external IDP the users acces ismaintained in the IDP not in the portal database.
2. Can developer invitation through the portal synchronize with or notify external IdP’s DB?
Not sure what you expect here ? the user is maintained in the idp .
3. Can Portal create users via PAPI with approved status?
I need to look into this normally the user signs up and it needs to be approved.
Regards
Dirk