@1
"1) never move the same piece twice"
++ Thus 1 e4 e5 2 Nf3 Nc6 3 Bc4 Nf6 4 d3 and not 4 Ng5, though it is not that clear.
"2) Don't waste time on unnecessary moves with rook pawns"
++ Lasker: only play your d- and e-pawns.
"the moves h2-h3 or h7-h6 are important to prevent the pinning of the knight on f3 [f6] by a bishop move to g4 [g5]." ++ It is often stronger to allow the pin and then play h3 or h6. Lasker: do not pin your opponent's king's knight with your queen's bishop before your opponent has castled O-O. There are many ways to unpin. Do not fear the pin.
"3) Do not move the queen prematurely" ++ Often an early queen sortie is the way to punish an early bishop sortie, like 1 e4 c5 2 Nf3 d6 3 d4 cxd4 4 Nxd4 Nf6 5 Nc3 a6 6 Bg5 e6 7 f4 Qb6
Likewise do not move the bishop prematurely: knights before bishops - Tarrasch.
"4) Do not start any premature or unprepared attacks! "
++ Capablanca: you can only attack after you control 3 of the 4 central squares e4 d4 e5 d5.
"5) In open positions, do not play to win a pawn if it results in you neglecting your development"
++ As black you can lose 1 or 2 tempi to win a pawn, as white you can lose 2 or 3 tempi to win a pawn. To refute a gambit, accept it. Thus 1 e4 e5 2 d4 exd4 3 c3 dxc3. You may have to defend, but you have long term prospect of a won endgame.
6) Put your king in a safe position!
++ Yes, castle early and often. Castle king's side O-O unless there is compelling reason for O-O-O.
The art of the opening consists of rendering effective the pieces which were initially blocked in, of freeing the pieces by a small number of pawn moves and placing them in favorable positions, and doing so as quickly as possible. One must make the most of each and every tempo, advancing move by move. The best way to develop the pieces is according to their value: first the pawns or at least one pawn, then the minor pieces, and finally the major ones - Tarrasch 'The Game of Chess'
The side which brings its pieces into play faster and better usually obtains the initiative as a result, and can attack the opponent first.
Here are some guidelines which a less experienced chess player must follow in order to successfully survive the complicated opening phase of the game. You must of course understand that these rules - as so often is the case in chess - are in no way absolute, and that you can sometimes break them. However, you should only do this if you acquire important advantages, such as, for example, a major gain in material, control of the center or the disruption of your opponent's development.
The principles behind mobilization
1) If possible, in the opening never move the same piece twice!
You should first try to bring other pieces into play!
2) Don't waste time on unnecessary moves with rook pawns!
(In praxis there are frequent exceptions to this rule. Sometimes the moves h2-h3 or h7-h6 are important to prevent the pinning of the knight on f3 [f6] by a bishop move to g4 [g5]. Nevertheless, you should weigh up such moves very carefully, because they cost time and can weaken your own castled position.)
3) Do not move the queen prematurely!
The queen is the strongest piece and it is very important to have it well posted. If you bring out the queen too early and too far, your opponent can gain time for development by attacking the queen with his pieces.
4) Do not start any premature or unprepared attacks!
5) In open positions, do not play to win a pawn if it results in you neglecting your development!
The time wasted doing this can lead to a dangerous lead in development for your opponent, and that can result in your coming under attack. But in closed positions the loss of a tempo plays a less important role.
6) Put your king in a safe position!
A king in the center can come under attack very quickly. In an open position, castling must be prepared as soon as possible. This also brings the rooks into play.