Yes , each player must always make a move in each turn . The rules do not allow for the "skipping" of a move .
No, each chess piece can only take one in a single movement.
The only piece in chess that is categorically not allowed to move backwards towards their own side is the pawn. Every other piece can move either away or towards their opponent in a number of idiosyncratic ways.
You can move your mum
A bishop in Chess can move diagonally in any direction as the path is not obstructed by another piece.
A chess piece which can move in an "L" formation that is on the black team.
The Queen
You can not skip your move in chess. You always have to move when it is your turn. If you have no legal moves in chess and it is your turn, the game is a stalemate.
With strict rules, yes.
The skewer is a horrible move in chess: it is a great move to use in chess to get a great advantage. A skewer is when a piece attacks an opponent's piece, that is stronger than the piece attacking it. It moves the piece out of the way, to leave a less valuable piece vunerable. It doesn't sound bad; but it is!
Once! Every piece gets to move only once per turn, and only one piece can move every turn, except in castling where the king and the rook move.
If you mean the Bishop. on the diagonal.
Yes; unfortunaely, "white" in the game of Chess, has the advantage, from the way the board is set (the bottom right corner is always white), to which pieces move first, etc.