Yes you can
plan to kill king
Yes, by that you capture a piece.
anything but a king
Not at One Movement
Chess is based off of war. Also it's just a habit.
A pawn can kill diangular foward or backwards
Yes , the queen can capture the king and this ends the game since the king's capture is the goal of the game of chess .
Absolutely, as long as it does not put the king in check.