Navisworks does not have a file reader for KMZ files and there is no plugin currently available to enable this functionality. There is an only a KMZ export function to get your model out of Navisworks and into this format (available from the Application Button > Export menu item).
If you think this would be useful functionality for the application, you can submit it as a product enhancement request here:
As for applying an image to a surface in Navisworks, you will want to create a new “material” for the image on the Presenter palette. (In the help file, this information is under “Edit Presenter Materials”).
1.) Open Presenter.
2.) Access the “Materials” tab.
3.) Expand the “Templates” option.
4.) Click and drag “Plain Texture” into the presenter material space on the right.
5.) Right-click this new texture and click “Rename”.
6.) Name the material appropriately.
7.) Right-click your material and click “Edit…”
8.) Access the Image File Name field.
9.) Click the button to the right of the field and select the desired image file.
10.) You can adjust the way the image is handled in your material if you are looking for more advanced controls. If you are, search the Navisworks help file for “Advanced Materials” for additional information.
11.) With your presenter material created, you can now drag and drop it over the appropriate geometry.