Can you launch right down at the near end of the runway where the river comes into the bay to catch a westerly, or is it too flukey?

Flukey or no, I think Gale force gusts might be a bit much for my 7m2 and slalom board

I think people still sail on the eastern side of the runways in strong westerlies for flat water.
Foreshore road has a little parking lot for plane spotters that gives access to the beach

yes that is the place, but it has been spoiled since they dock big ships and built the rock groins, now is more choppy as soon as you get a bit far and less room for jibing. If you want to have fun in W go to Budgewoi or Primbee, but need a (high rake) weed fin