I’m also intrested in the same topic, so I asked directly to Universal Robots and they told me that they are not allowed to share these informations. There are some values of the Inertia tensors on Internet in some papers, thesis or also on the ROS website. Nevertheless, they are not exactly the ones of your robot, of course, but I think that they have been calculated through a model, so I have no idea how “correct” they could be, but it’s better then nothing.
For other parameters like friction, there are some data in the calibration files of your robot, just download the magic files form the Universal Robots website and follow the instructions to copy those files on a USB drive. YOu can also have a look on them directly on the robot by going on the Expert Mode (there are also the corrections to the DH parameters for your robot).
Hope that this information could be helpful to you!