1. Does the USB ethernet share the same bus as the USB host port (like the raspberry pi)?
It’s a discrete device with shared power.
2. What kind of power draw can we expect from this lil guy?
Peak draw is 2.5amps at 5volts. The mean draw is around 1.5amps at 5 volts.
3. On the info graphic, you mention power over dual microUSB. Does that mean both are required if you don't have a 12V barrel plugged in? Are these ports power only?
You can power the device over any combination of the 3 ports as long as you meet the wattage requirement.
4. Do you forese