Two captured barbarians are worth one victory point, but a single barbarian initially has no value for a player. In a combination with Cities & Knights or The Fishermen of Catan, this means that whenever you can play cards (Master Merchant and Wedding) against the leading player(s), they are not affected by it if a single captured barbarian provides them with half a virtual point more than you.

His owner places him on the next free path.

Yes.

Yes.

Yes.

The conquered settlement still exists. The trade route is interrupted, that is, only the road segments or the ships count toward the Longest Trade Route. However, the ship and the road segment adjacent to the settlement are not “open.”

The knights remain at their current hex. Furthermore, they may immediately intervene in the next battle if there are more knights than barbarians at an adjacent hex.

After each battle, you immediately determine which knights didn't withstand the battle. A knight wounded in a battle can't participate in another battle.

No. First you have to move all knights, then all the battles take place.

No. Barbarians may only be placed on coastal hexes.

A knight placed at the castle hex must be moved immediately; to do this, however, you have to wait until the end of your turn. You can move your knights after you have finished trading and/or building. Knights you just placed at the castle hex must be moved.

Yes.