1) There is no “firearms prepared symbol”. Use this rule for terrains that bear the “firearms prepared" words in the table of terrain.
2) this is a non obligatory attack (because of the dotted line and because clan c is not in attack). You cannot attack only one though. If you attack, the normal rules apply so all enemies have to be attacked.
3) The 3 conditions apply, according to the situation.
if Shingeki vs Yari Fusuma -1 on blue die
and / or firearms prepared
and / or non obligatory attack
They are listed the way they are only because of the layout.
4) of course, if you choose the non obligatory attack, then there is no attack and all other conditions become irrelevant.
I hope this is clearer. Else, please, ask again.
Francois. That is very clear now. On point 2 I assume this is because if a clan does chose to attack when in defense order all units of the clan must attack?
Thanks once again for answering my rules questions!