Anderson considered that the status quo at Moultie presented too tempting of a target for the hotheads in Charleston, but that they would thing twice before trying something rash against Sumter. As for signs of trouble, remember that hostile mobs formed when the garrison tried to draw so much as a dozen muskets from their own arsenal in Charleston - of course the South Carolina government was more that happy to place guards on the U.S. Arsenal to make sure it wasn't disturbed (until they were ready to seize it).