Connecting the rooks

@1
"Is it so important to connect the rooks"
++ Yes it is very important. Rooks are the most powerful fighting units after the queen and there are two of them. So it is important to activate rooks. A rook is most active on an open file. Suppose your opponent puts a rook on an open file. Now his rook is active and threatens to invade your back rank or second rank. To neutralise its activity, you generally have to oppose it with a rook of your own on the same file. If he captures your rook, and your rooks are connected, then you can recapture with your other rook, after which trade you control the open file with your rook, so you have an active rook threatening to invade his back rank or second rank.