I haven't used an adapter for few months, but iirc it doesn't connect to those, instead there is a bunch of pins in the battery area. The serial port should be in the blue circle.
Regarding the red one, i've never used, but i wouldn't be surprised if it isn't available in production units. Lots of test points disappear while the board goes through successive iterations of design.
Or it could easily be a peephole on the wifi or gps serial ports.
And, to close the pads discussion, i was referring to the 2 pairs of _square_ pads that are in the upper area. one of them is intersecting the red circle. Those are the speakers.