basically, you want to route cellular data back and forth to your pc.
Just to be clear this is more a linux network routing issue and not anything related to the platform itself.
We have investigated routing data to ethernet port here: Routing Ethernet to 3g/4g
You can start by looking there or goto other forums like (https://android.stackexchange.com/questions/119147/how-do-i-route-traffic-from-wifi-hotspot-to-usb)
However, if that didnt work we will work on this and get back to you. Your frustration is understandable but a bit of looking around is needed for these kind of questions.