Q: Is it possible to export as many issues as I want?
A: YES, you can export all the issues that you want. Keep in mind that if there are many issues the process may take so much time
Q: Can I export more than one extra content in the same export?
A: YES, you can export the Attachments, Comments and Transitions all together.
Q: Why the transitions are not available when exporting to CSV?
A: The target of exporting to a CSV file is to import into another JIRA instance. Doing that makes no sense to import the transition log because the new instance may have different workflows and JIRA doesn't allow it.
Q: Does Exporter allows me to export comments and attachments and re-import them to a different JIRA instance?
A: Yes, the export files you get is totally compatible with another JIRA instance, regardless of the platform (Server or Cloud). You can even export/import the attachments!. Just follow the JIRA instructions to import them.