Here's a list of mostly unanswered questions I wish were in the FAQ, from a noob's perspective:
When training a crew member, it says he is unavailable: does this mean he is not helping your performance in battle and not gaining experience during training?
What is the purpose of the communication tower and what do range points do?
How do we know if belt or deck armor is being hit? All shots even close range appear to be 'lobbed' up in the air a great deal. Is belt vs deck hit based on distance between ships, or specific gun angles, or both?
When upgrading buildings, such as steel mill and oil depot, does production halt until upgrade is complete?
Do crews transfer between ships? Answer: No.
What is the maximum number of components (slots filled) you can have on a ship? Answer: 8; this means you can't fully equip ships.
How do you aim at planes with AA guns?
If my ship is not repaired 100%, will I enter single player and/or multiplayer games with lower than maximum hitpoints; will this be reflected in my hitpoint bar or will it simply show 100% at all times during the start?