I have an Arai Vector, it's awesome. You can't put a price on safety, but also it's really comfortable and has good ventilation.
Also, all Arai's are handmade so I'm told! Worth the extra in every way.
That's just to momentarily flash your main beam on.
Here in Britain it is used to let someone in or across you, or as an act of aggression! I have used it about once to let someone in in traffic.
I wouldn't use it when passing someone as they would probably think I was being a smart arse...
Down as much as possible. I know what you are saying about the enclosed feeling, but I overcame this by being obsessive about cleaning the visor. I keep glasses wipes at work, at home, in my gear! I was riding yesterday and thought it must be up as it was so clean, I even checked!
It paid...