Re 1: In the nVidia Control Panel>Manage 3D Settings, select the Global Settings tab. Scroll down and click 'OpenGL rendering GPU'. You should now be able to choose between 'Auto-select' or 'GeForce 930 MX'. Also, go to Set PhysX Configuration and click 'Processor'. This should open a drop-down list with your graphics engines.
You can also click Desktop on the menu bar and select 'Display GPU Activity Icon in Notification Area'. Now you can see how much the nVidia GPU is used in the bottom of the screen.
Re 2: If your nVidia card is enabled, it should engage whenever the need arises. Update the driver. Also, you could try and disable it and restart the computer. Then enable it again.
Re 3: Your ASUS BIOS menu is probably different from those in my computers. Browse around and see if you can find any feature that allows you to select graphics engines. It may show options such as Auto, IGP, PCIx or something similar. I don't know what your BIOS looks like, but I'm pretty sure there is such a feature somewhere. When you find it, make sure it's set to 'Auto'. Again, this is tricky stuff so you should only change the settings if it says anything other than Auto.