I always assumed that cameras with 1920x1080 sensors (like the F3) were four pixels for each pixel (R,G,G,B). Does this mean that those cameras only actually have 960 horizontal red and green pixels?
It depends from actual sensor used (for 1920 sensor, yes, they use interpolation, as any other camera with bayer sensor).. You must also remember that most footage is in 4:2:0 or 4:2:2 (all TV broadcast shit is in 4:2:0 as I know).