Ok, everyone complains that the current object management tools are kinda rudimentary.
Would it be too hard to make plots of land have an inventory of sorts?
Divide it into three folders: objects owned by us, objects owned by groups, objects owned by other people.
Right clicking on an object in that folder should provide options to zoom on it, delete it, or return it.
Selecting multiple objects and then hitting delete would delete (or return) them all from our plot.