If you just want to change the default measurement for line thickness (I think the only other thing that's in points by default is text size) with nothing selected click on the outline tool then on the outline pen dialog button. Draw will come up asking to what object you want to apply these setting to. Just select graphic, then in the dialog box change the measurement sytem to inches and hit okay. Now every new object you draw will have the properties of everything in that dialogue box and everything already drawn will be measured in inches.