Organic molecules on the surface. Their origin is uncertain.
Most likely from some abiotic process/phenomenon.
Yup, but it means there's a chance that there might have been organic molecules on the surface when Mars was warmer and wetter, to provide ingredients for life. Although I'm betting it's more likely that there's life under the surface of Europa or Enceladus than there is on Mars.
(On a side note, I'm continually impressed by how much mileage (figuratively and literally) the NASA teams get out of their missions.)