Hello
Answer 1: yes, yes
Answer 2: Basically you are right... if you can see dust you have LoS somewhere near the dust. That point could be targeted by a FO. And you can’t target anything if you have no LoS. You can discuss about this but I don’t mind. This helps to keep the game playable when playing H2H. Peolple could buy tons of arty and bomb any most likely hide spot until they win.