Which versions are supported

SAP Process Integration 7.1, PI 7.11. PI 7.3. If is enough request for XI 3.0 or PI 7.0 it is possible to back port the app to those versions. Let me know if it is an issue for your, and it see how difficult it is to back port.

Can I change the domain

It is not possible to change the domain on Amazon Simple DB. If the domain is changed, it is not possible to search for the messages in the old domain. It is the reason for only having one domain

Unable to encrypt message, Error while accessing keystore in module processing

This means that the key specified in the Amazon bucket is not defined correctly or that the module does not have access to use the certificate. See the certificate section in the guide.