[Edit] Now that you have sorted out the USB problem, it would be interesting to try the epkowa driver again in Xenial.
Run it with Xsane.Just out of curiosity, here is something to try that might work with epkowa.
1. Open the file /usr/share/iscan-data/usb
2. Add the line: usb 0x04b8:0x111c
3. Run: scanimage -L