Are all of the buildings in a set connected by roads and eligible for the bonus or just the exact connections. Example, Is the ore mine connected to just the iron foundry and coal mine or is it also connected to the steel mill, the coking works, and the power plant.
You look at each little road segment and award points if a player owns both ends. Thus, if you own the Iron Mine, the Iron Foundry and the Steel Mill, you get points for the road between the Iron Mine and the Iron Foundry, and you also get points for the road between the Iron Foundry and the Steel Mill. You do not get points for a connection between the Iron Mine and the Steel Mill per se.
Regarding the auction phase, in a four player game, you turn 4 tiles face up and player 1 is the auctioneer. Either he sells them or keeps one and passes the auction to player 2. After the first 4 tiles have been acquired by players, each player receives a coin from the bank and 4 new tiles are turned up for auction.
You auction the tiles one at a time, not as a set. So Player 1 picks a tile and auctions it. If someone else buys it, Player 1 auctions a second tile. Otherwise, the right to auction passes.
Let's say player 3 was the final auctioneer for the first 4 tiles. Does player 2 become the auctioneer when the second set are turned up or does player 3 retain the title of auctioneer?
Player 2 becomes the auctioneer in this case. The right to be first auctioneer for the next complete set of tiles moves around the table one person at a time regardless of what happens during the auction.