Agreed with Sandy here! Marketo is a Marketing Automation Platform that uses PII (e.g., Email Address, Phone Number, etc.) data (ideally collected via reasonable means) to send out marketing/operational content to people. It's not very possible to grant someone access to the Marketing Activities section with 0 possibilities of them being able to see the PII data. Marketo, especially the core sections like Marketing Activities and Lead Database are all full of PII data in the first place. There are certain third-party platforms available that use Marketo's APIs internally to create/edit/update marketing assets in Marketo, you can possibly explore those options so your external users cannot possibly see any PII data while making updates to the assets in Marketo via a third-party platform. Of course, not everything that could be updated via GUI could also be updated via the APIs,e.g., editing a campaign flow/SL isn't possible via API, and hence wouldn't be possible by any external third-party platform leveraging Marketo APIs too.