Hi 

You don't need to copy-paste these commands each time, this settings are saved permanently unless you revert them back manually.

To remove paper margins (dotted rectangle) you need to use this AutoLISP statement:

Command: (setenv "ShowPaperMargins" "0")

BTW, due to the fact that you showed that dotted rectangle in your drawing, I noticed that you have incorrect Page Setup for Layout: paper size assigned to Layout is smaller than Title block you are using. Of course, you can use such setup, but it would be more correct to adjust the paper size according to Title block you are using.