ERC on imported schematic errors on power connectors

Schematic
3

See this FAQ: ErrType(3): Pin connected to some others pins but no pin to drive it

The short version is that ERC expects a pin of type “power output” on +12V net, but doesn’t find one, so it thinks the net is undriven. As a human engineer, you can see if that’s actually true, or if the net is in fact driven by something that KiCad doesn’t understand is a power source (for example, a connector to an external power supply). There is a dummy symbol PWR_FLAG in the power symbol library that can be added to the net to politely tell KiCad that the net is actually driven.

to answer your questions:

  1. From what I’ve seen, blendtec blends most things
  2. It might be or it might not be; is that net actually getting +12V from somewhere? It probably is, and KiCad just doesn’t understand where it’s coming from.
  3. Yes, you can layout (but check that it’s not a real design issue!)
  4. Add a PWR_FLAG to that net, assuming that it’s not a real design issue.