I'm no fan of excessive use of force by LEOs, or of arrogant government. Nor do I think we need to ask "how high" when Caesar asks us to jump. (FWIW, I believe some Christians stretch the meaning of Biblical passages like Romans 13 to advocate absolute nonresistance to state tyranny.)
Nevertheless, we have to recognize that it is impossible for societies to exist without public utilities such as roads, fire departments, telephone lines, etc. The U.S. Constitution permits Federal government "takings" of private property provided due process is followed and just compensation is offered. State constitutions generally have parallel provisions. Provided the South Carolina authorities followed the constitutional guidelines, they were justified in requiring that the family leave the premises.
I agree. If you truly want to be left alone, don't get a house next to a main road. If the story is that this is family land going way back- perhaps this guy (the old man) had an old grudge regarding his land and roads, etc. It isn't clear what the whole story is. No excuse/rational reason to shoot anyone.