... and according to the photos and description it should be a V2

Thank you very much for your comment, it will be corrected shortly!

The NZXT CAM software, which is used to control and display the temperature of the Kraken Elite 360 V2 CPU water cooling system, is not officially compatible with Linux. There is no native support for Linux, and NZXT does not offer a Linux version of the CAM software. However, approaches and alternative tools such as "liquidctl" exist in the Linux community that attempt to support some functions of Kraken coolers on Linux, but these are not official and may have limited functionality. The main cooling function (CPU cooling) works under Linux independently of the software, but controlling the fans, RGB lighting and displaying the temperature via the LCD display are not possible or only possible to a limited extent without CAM software or a compatible alternative.

Yes, it is the V2 version.

You can replace the fans of the Kraken Elite 360 with Noctua fans as long as they have the same size (120 mm) and connection type. Note, however, that the fan compatibility also depends on the mechanical fit and the electrical connection type. It is advisable to ensure that the new fans are compatible with the radiator and the system's controller.

Yes, it's the V2 version with the big screen

It is possible to add NZXT F120 RGB fans to your liquid cooling system, but you should check for specific compatibility with your NZXT H9 Elite case. F120 RGB fans are generally compatible with NZXT systems, but make sure your case has the necessary slots to install them. For more details, consult your case manual or contact NZXT technical support.