Couple of questions

[Plain Ian]

Thought I could walk back into this game after a few years off but........

Visibility?
So its a Dawn Turn, enemy units are visible to me 2 hexes away but I cannot indirect fire on them? Quick look at rules says Dawn has a "nominal" visibility of 2 but an "effective" visibility of 1? So Dawn is a special turn?
Visibility on Weather Reports says 3-5 km?

Indirect Fire
Alternative Indirect Fire has been selected as an option. Nebelwerfers and artillery fire ok with one shot. Hvy weapon units and mortars get to select targets in hex? Can't see this in rules and stupid win 7 doesn't support win help files so can't read the Options Help fie?