Thanks for your feedback.
- Password-protect and encrypt documents
We have already logged the feature, SAASPDF-68, for encrypted PDF support in Aspose.Pdf for Clouds. It has been implemented and will be available soon.
- Inject text items into existing documents
We have logged a new feature, SAASPDF-130, to add text in existing PDF document, in our issue tracking system and will update you as soon as it it resolved.
- And maybe a refresh of the .NET SDK for Cloud (poor code quality).
Thanks for suggestion,we will look into soon and will improve it.