1. Anything not attack from a units front arc will attack its rear defence value - so directly to the sides, in the same hex, or behind it all use the rear defence.
2. Units don’t block line of sight; terrain blocks line of sight passing through it but not into it. The forest hex will block line of sight that passes through it. So the tank could attack the infantry in the forest hex, but not an infantry behind the forest hex.
3. Provoking Defencive Fire is a free action - it doesn’t count against that unit moving/attacking normally during the following phase.
4. SAs that add dice, such as Stars & Stripes or Flanking Attack, specifically say so: “This unit rolls one extra dice…” SAs that modify the attack dice, such as Crack Shot, also say so “This unit gets +1 on each attack die”
5. Yes. They are considered to connect to all other adjacent town hexes despite how the roads may be depicted on them.
6. No. Amphibious states it can move into water hexes not marsh hexes.