Wideband question. V-Offsets, gauge vs ECU?

We know that voltage offsets affect/skew 0-5V accuracy of our wideband output to the ECU.

We know that the serial outputs is although slower response is more reliable.

We know that CAN signal is superior to all.

Now, with all that being said can you please:

1. Confirm my above statements are true or false

2. Confirm that the order of reliability from best to worst is CAN>Serial>Analog

3. Answer if the AFR gauge, not the ECU analog output, but the gauge itself is also voltage offset sensitive?

4. Help me understand grounding for EACH WB component from a. 4.2/4.9 LSU Sensor b. EUGO box c. Gauge to, d. output to ECU

Many Thanks,

Dmitriy