Hey Lak,
1. Yes, the controller is only 3DOF, while the HMD is 6DOF.
2. It is possible to move the controller in a rudimentary fashion, as Dario pointed out, you can use the arm model for that. I think there's an example in Unity, otherwise I think you can copy the Daydream implementation in GVR. And I believe the Focus manual also says something about this. It's not great, and not suitable for new users, but it does work. I've used the touchpad to move the controller forward and backward, making it somewhat possible to interact with things. But again, it's not great.
3. I read that the 2.0 firmware will support camera tracking of the 3DOF controller, enabling 6DOF as long as you look at it. This will undoubtedly work better than the solution described in point 2. But I'm sure it's coming "soon". Let's hope that's not in Valve time. Otherwise, the Finch Shift looks awesome, but I haven't been able to find anywhere I could order it.
Kind regards,
Peter