What's the difference between installing coilovers, and dropping the car 1, 2, or even 4 inches?
Installation is the same. Your decision on strut tube sectioning should be based on how much you plan to lower the car. As detailed in the archives, the struts should be sectioned if you plan to lower the car more than 1.5-2 inches. Otherwise, just get a Ground Control kit, shave the perches, and go.
I don't understand your reasoning behind getting inserts with a "2in shorter extended length"? I recommend re-reading some of those threads until you have a solid grasp of what's involved, and the reasons behind performing certain tasks.