Hello,
For the GUI, I can recommend you to use a THCI example, you will be able to send commands to though serial.
The thread network can be made, but you will need to create some application on your own or change the provided examples to make it work, also, you will need to set some options or know some data of the devices to be able to create the list before joining.
You can check the Kinetis Thread Stack Application Developer’s Guide and the Kinetis Thread Stack Demo Applications User's Guide, there you will find with a little more detail on both the border router a, the HCI commands and some of the stack configurations.
Those documents are available in the SDK documentation of the KW41Z freedom board.
Regards,
Estephania