The product rule needs to be mapped to the pipeline in the deployment manager.
In the product rule you can include the associated data instances or the specific data instances, and they would get considered for the packaging, export/import.
If your development teams are following branch based development, then upon each branch merge the ruleset versioning is handled through deployment manager.
Review process is also tied with the branch based development approach. We have a new branch review process which helps the teams to get the technical reviews done.
Pega to Jira is not available through deployment manager as of now, but you can find components which give capability to integrate Jira with Pega in Pega Exchange (PDN).
Pega does have REST APIs to perform the import/export actions, and you can find more details about them in PDN with reference as prpcServiceUtils.