While not guaranteed, I am currently working on updating the add-on to work with 2.8.
Yes, there is an example of the command required for successful command line rendering in the Documentation.
Not currently. At the minute the render border is set at the beginning of the render and it is only possible to update it when the rendering of the next frame starts, so whatever render border is set at the beginning of the render will be set for all render layers.
The only solution at the minute is to render out the render layers separately, setting a different render border between each render and then combining the render layers later in the compositor.
This is a question I get asked a lot so I will continue to look for a solution to this.
(Last updated: 13/09/17)
The add-on can only track the actual position of the object in the 3D View. If the camera has settings that changes/warps the position of the object in Rendered shading view (as is the case for Panoramic camera types), then the add-on unfortunately cannot track its rendered location.
The only solution to this at the minute is to manually animate the render border by using the 'Keyframe' mode of the add-on, while in rendered shading mode.
I will look into whether this can be improved.
(Last updated: 16/08/18)