No. You may play Development Cards only on your own turn. The special building phase is not part of your turn.

No. If, on your turn, you have reached the victory points (including your Victory Point Cards) required to win, you may reveal all your Victory Point Cards at once.

• No – if a player reaches the required number of victory points during his turn, the game ends as specified in the rules.

• Yes – if the game ends at a point agreed upon by the players before or during the game, after which each player – beginning with the starting player – may take one more turn, that is, the game ends when player 5 or 6 has taken his turn.
  In this case, it is recommended to include another special building phase after player 5 or 6 has finished his turn, so that the players can use the resources they just have received. Otherwise, the last player to take a turn is at a disadvantage, because no one will trade with him any more. The order in which the players take their turns would have too much bearing on the outcome of the game, because during the last round the number of trades performed would diminish player by player – after all, why should a player who is no longer allowed to build keep on trading?
  This rule is also recommended for 3-4 player games, because otherwise the last player would hardly have an opportunity to trade. Therefore, in a 3-4 player game, a one-time final build phase for all other players would take place.

No. You can only win during your own turn.

Place the harbors adjacent to terrain hexes so that both harbor locations border on land.

No. This rule is a guideline of how to proceed if you play the game for the first time. Experienced players will most likely choose some other way of determining the starting player.

The rules do not prohibit it. However, common sense should tell you to play in such a way that your current opponents will also want to play with you tomorrow.

Yes. That’s how it’s specified in the game rules.

No. A Knight Card that hasn’t been revealed is like a lottery slip where you marked six winning numbers but then didn’t submit it to enter the drawing: it’s useless!

In principle, yes; but on Catan the circle is a hexagon. When counting the individual road pieces, it doesn’t matter whether or not they are built in a more or less straight line - what matters is that they establish an uninterrupted connection between two intersections. This is why six road pieces connected in a hexagonal fashion still count as six road pieces.

No.

By building a settlement on an intersection of the Longest Road. Needless to say that you must observe all building rules when doing this.