Chess openings

Your all game depends on your openings.If your openings are good enough it means that you have good command on your game.

This statement is somewhat true, but you can catch yourself in a blunder if your opponent doesn't play to your opening, thus you'll need to catch up in the middle game or the end-game.

I disagree. At the beginner level the goal of an opening is control of the center, development of the pieces, safety of the King and then the game plays. Usually there are many errors from both sides, pieces hanging, missed tactics etc. 

Once you improve and lessen the obvious mistakes, choosing an opening and knowing it becomes more important as you become familiar with the tabia you understand the positions, tactics and endgame arising from it.

For most people common sense in terms of development, center control is enough to get them by. Too many people think they know an opening only to lose a piece or get checkmated a few moves agter their "knowledge" has run out

I disagree too, unless you're at super-GM level, you will make a bad move or an inferior move which has nothing to do with the opening. eg. blunders, positional mistakes, trading wrong pieces, moving the wrong rook, making a mistake in the middlegame or endgame.