Welcome to the forum, Barbarossa.
In the “Player Help” section of this forum you will find lots of threads with maths concerning your first question.
Ask your rules questions for Europe 1940.2 in this subforum. We have a FAQ/question thread stickied - or feel free to open a separate thread.
For 1942.2 please use the dedicated subforum.
Also feel free to contact me by PM in case you experience language barriers.
Have fun :-)