[c_of_red]

4. is already there, or at least it is in the CD version. It has been so long since I saw the DL version I can't remember.
On the screen where you adjust the range gate for op fire and set the op fire filters (CD version) there is a switch that highlights ALL the hexes that unit has LOS to.
The 'click 360' trick works for infantry units, since they get a slight increase in searching percentage in the direction they are facing. I think it is that slight bump that causes a new "seen/not seen" calculation. Rolling snake eyes isn't easy, but if you don't roll the die, it's impossible. I don't think it works with vehicles, since they don't get a searching bonus for their facing (I am not real sure about this, since it is something that can change over the course of various patches of the game). I know that the original SP releases gave that searching bonus to infantry units and I don't recall seeing that it has been taken away. Being a lazy American,I don't do the 'click 360' anymore, now that I have a nice button to do it for me. I don't know if that button recalculates the "seen" units or not. I imagine 'not'.
I have never noticed it working with vehicles, even though I have done the 'click 360' many times with scout units.
My SOP for scouts is to move 1 hex, click 360, repeat until I see something or have reached my new hide. I do that because I know that moving to a new hex DOES generate a new "seen/not seen" calculation.
The Law of probability says that all die rolls have the same chance of being snake eyes ( somewhere around 2%, IIRC).
The Law of Casualty ( cause and effect) says that if you keep rolling the die until you get snake eyes, the chance of getting snakes eyes is 100%