Open Source Document Management System | OpenKM

Hi, I'm currently evaluating the community version and am in the process of duplicating the some of the documents from our current system to openKM.
I am importing the structure and files using the .net API and have some questions regarding the properties of created files.

Is it possible to retain the created and modified timestamps of imported files?
For each file revision import does the process of checkout/check in need to be actioned?
Does the professional version have a more feature rich API?

Thanks.

1- You should use repository import from administration tools either API import.
2- Yes, in professional version there a more wide API, you can check yourself comparing community SDK https://docs.openkm.com/kcenter/view/sdk4net-1.2.3/ with professional SDK https://docs.openkm.com/kcenter/view/sdk4net-3.4.1/
3- About filesystem timestamp currently in the professional edition, we are making some improvements for huge import and probably we will introduce something in this direction. When in past customer wanted the time stamp was needed to build a small procedure for doing this kind of import ( because API itself, does not have this purpose ).