Starcraft 2 - More 2v2 Ladder

I'm gradually increasing my ranking with 3 different teammates in the 2v2 ladder.  What I've learned is:

• Scouting is more important the longer the match goes on
• There is such thing as attacking too late with a rush - your opponent's economy will outstrip yours the longer you wait.
• It is vital that your opponent send whatever he has with your rushing force.  Even 3 marines can make a big difference when the number of defenders is so low.
• Preventing your opponent from expanding or killing his expansion only works if you have enough troops to hold back his counterattack.
• It is usually better to keep attacking a weakened opponent than to stop and go heavy economy.  Usually, you will forfeit your advantage and the scales will balance again, since you sacrificed early economy to attack, and the small amount of damage you can inflict that early in the game usually balances the cost of making the attack in the first place!