1) Does the defender bonus for front and support of river attacks apply on every combat round? *Unless para drop. While the attacker modifier only applies on the first round.. is it right that the defender has the bonus for the whole battle? (battle chart only has the *lasts only for 1 turn* on the attacker side.)
Both the attacker and the defender are modified for the first round of combat during river and amphibious assaults. I'll make the change on the battleboard and make it more clear in the rules
2) Does the printed Naval AA reduced somehow if the naval unit is out of supply?
Out of supply AA die rolls are modified by +1. This is noted on the ground battleboard, but not as clear on the naval battleboard.
2.1 Does ground AA reduced if out of supply?
Yes - noted on the battleboard. I will make it more clear in the rules.
3) Does the printed Naval AA on the counters reduced for italy, if italy has less than 8 VP-Points? (it is said all combat values) example: battleship down to 3 AA)
Yes - all values (including AA) reduced by 1.
4) While the Leader is not in frontline on the first combat round.. is it right that also he doesn't applies on the first round of reinforment table? So NL for first round of landing? Right?
Yes
5) If subs kill a carrier, is the plane also dead if it was fighting in naval combat? or is it allowed to retreat. If it is allowed to retreat. whats the range for retreating? half range or range?
This is a good question. I think the ruling should be, the plane is eliminated. The reason I say this is because sub combat (whether it is movement interdiction or at the conclusion of the battle) is happening after the battle is over, or before it begins (in the case of interdicting movement). I think the plane should be killed.