to answer question #1 you need to specify where your extension is. If it's between the socket and the torque wrench you need no conversion. If it's on the torque wrench handle being used for leverage then it's going to change your final torque amount. I don't have a chart or anything, I just use the proper wrench for the job to ensure accuracy. Question #2 is 12 in. lbs. = 1 ft.lbs.
