It takes as long as it takes on the day. MCT is the time airlines are prepared to offer connections on not necessarily the time for passengers to complete the connections process.

As this is on one ticket you will be protected if your SAS flight is delayed.

Why should SAS give you a seat assignment for the front of the plane when your ticket does not allow advance seat assignments? People have tight connections all the time hence the apparently unhelpful agents dealing with a passenger wanting something they are not entitled too.