I have a question about the 1859 scenarios in Risorgimento: the rules state that 
the Austrian player can use rail march in Tirol and Venetia, but can he also use 
rail march in Lombardy ?

No. The Austrian command unloaded reinforcing units in Verona; the rail line 
was not yet up to the heavy loads (had only recently opened to Milano).
 
- in the 1848 scenarios, Austrian fortresses start with very few CFs. When 
replacement points are available, can the Austrian player add them some CFs 
(up to their full counter value) ?
 
Answer: Yes.
 
- when an assault on a fortress is repulsed but is "technically" a victory 
(defender fully demoralized for example), is a victory taken into account 
(for the National Will adjustment), or shall we consider that a victory can 
only be awarded if the fortress is taken ?
 
Answer: Correct. Must take the fortress for it to be a victory.
 
<< - the rules state (14.3) that "most political markers must be played 
immediately, though some may be retained at the player's option", but the 
Political Events chart (page R16) does not specify which markers are to be 
played immediately and which ones may be retained.

play them immediately unless the description states otherwise (most if not 
all those in Risorgimento are played immediately as I recall)

- 10.4 (Combat Results): the "Honors of War" marker has no effect if drawn by 
a defender or by an attacker without artillery. It happens that as most 
combats do not involve fortresses, this marker is usually very negative 
towards the side drawing it, as it means "no effect". Is this voluntary from 
the game designer ? Is it possible to "ignore" this marker and draw another 
one when a battle not involving fortresses is resolved ?

(this question is also valid for the other games of the same series: 
Austro-Prussian War, etc...) >>

draw a fresh marker
 

Movement: is the cost +1 for a river and +2 for a major river (as stated in 
the terrain chart) or +2 and + 4 as stated in rule 9.8?

--terrain effects chart should be correct.