ORIGINAL: Speedysteve
1.) HQ's - what specific bonus do they give to the troops under their command? Is there a hex range they need to be in to benefit?
HQs/generals are important for 2 reasons:
1) You can use them to play command cards (each general has his own deck of cards, stats and command point rate)
2) Generic combat bonus: The combat bonus a unit gets from their HQ is a direct bonus on both its offensive and defensive striking power (off/def atk) and vulnerability/defence (hitpoints). So this can be very powerfull!
The calculation of the bonus is rather complicated but doesn't really need to bother you because it is listed for you in the officer tab (Combat bonus XX%). Just be aware of two things:
1) A unit needs to be within 5 hexes of its HQ to receive the full bonus. Beyond that, the bonus is reduced step by step. (you can turn "HQ Power Range" on in PREFS/Map to get an overlay).
2) Don't assign too many units to a single HQ. Keep an eye on the "Stf:Trp ratio" (Staff vs. Troops Ratio). If you assign too many units to the HQ, the ratio will fall below 1 and the combat bonus will suffer.
3.) The truck symbols on the road (in the attachment) - I assume they reflect road congestion?
Yes. Here is how congestion works:
You can check the status of road links between hexes in the detailed hex information tooltip. In the lower part of the tooltip, you will find two lines of values, labeled: "traffic points" and "max traffic points". The first indicates how many traffic points have already been used. The latter indicates how many traffic points the link can take (depending on the type of road). The values that follow correspond to the links to the neighbouring hexes like this: north, north east, south east, south, south west, north west.
A unit that is moved along a road link generates traffic points (unit weight *5).
Supply that is moved along a road link generates traffic points (0.1 per supply point, 0.3 per fuel point).
(Air strikes also generate traffic points)
As soon as the traffic points exceed the road capacity, a yellow truck symbol will show up. The positive effect of the road on movement speed (AP expenditure) is now reduced(both for troops and supply). Once traffic points exceed the road limit times four, the effect of the road is negated completely (which means units and supply use the ordinary movement costs of the target hex). As supply can only travel 100 AP from a supply source before the first malus sets in, clogged roads are a problem for supply.
At the start of each turn, traffic points in all road links are cut into half (thus a big traffic jam might take some time to resolve).