Is the scale related to wind speed, or barometric pressure, or both..and are the two directly related..i.e. if a storm has a really low pressure count, will the winds always be high?
Wind speed, although it is mostly indicative of how destructive the hurricane would be if it were to make landfall.
yes...wind and pressure correlate relatively well....it may take one a couple hours to catch up with the other.
the official scale rankings are based on sustained surface winds only.
They're related and affect each other, but a specific pressure does not always mean a specific wind speed.
The more the pressure is lowered, the quicker the surrounding air will try to rush in and fill the void. Of course the coriolis effect sets it spinning.
yes, yes, yes, yes
Sometimes the wind will lag slightly behind the pressure - if the pressure drops suddenly, it will take a couple of hours for the winds to strengthen in reaction to the pressure drop.