Connect a USB hub to the Raspberry Pi and then connect the USB WiFi adapter and 3D printer to the hub.
Astrobox supports most USB web cameras, like the logitech C920. There's currently NO support for the Raspberry Pi camera module.
At the moment (version 0.4), you can only monitor the web cam during prints. Simply click on the camera icon in the UI to update the web cam photo. It's not a live preview, just a photo - this may improve in future versions!