The "export rulebase to csv" is mainly for offline visibility and search of the policy. In order to be concise and readable, it has just part of the policy information. Also, csv files are "flat" and do not hold well the hierarchical and object oriented nature of our policy.
If you need to export and import policies or rules, you can use the below tool:
https://github.com/CheckPointSW/ExportImportPolicyPackage
It is open source, but maintained by our R&D team. It uses our APIs to export and then insert the objects and rules, and takes into account multiple references to the same objects.
Please let me know if this answers your use-case.