Were they the two F-16s that took off without a weapons load? If it came down to it they were going to have to ram the plane and then eject.
I can't answer the weapons question, but I doubt they were heading that way to whistle dixie (with apologies to Clint Eastwood). I think that they meant business, but weapons load wasn't visible.
Pretty sure those were DC Air Guard. They had just returned from an Air to ground training mission, they were not part of the ANG's alert force, such as it was. They did a hot refuel and launched with what they had, which was not nothing, but was only training rounds in the 20 mm drum. They could take out an engine, or better yet the cockpit, but they'd have a hard time doing enough damage to destroy the aircraft. But shooting up the cockpit might have worked. In the event, they didn't get a chance to find out, thanks to the Militia of Flight 93, who brought down the plane before the Guardsmen had to be burdened with such a task. It would have been a heck of a burden to bear.