Are there any cmdline options for Nexus Dock ?
I want to exit the dock trought a .bat file when i run a game, when game exits i would return the dock.

If there are no options, would it be possible to implement an option that when a certain application launches the dock would go into "pause" state or even exit ?

Nexus already goes automatically into a pause/reduced functionality state when you run a full screen application.

The feature you mentioned was actually considered many years ago (e.g.; a setting in a shortcut's properties to make Nexus automatically exit when you run that shortcut, leaving only a 'watchdog' running, and then automatically launch again when you exit it) but I decided against it for a variety of reasons.

First, many games use an intermediate 'launcher' to launch the actual game, the launcher immediately exiting afterwards - this would defeat the purpose and create another layer of complexity/application exceptions. IIRC, even Raymond Chen (Microsoft's in-house guru) talks about this in one of his blog posts.

Second, computers these days are so powerful (and have so much RAM) that there really is no need to do this.

In other words, adding such a feature would be more trouble than it's worth.