For launch, they get out fire hoses and clean everything off. Then people walk over looking for any debris. Even a piece of gravel can kick up and damage the vehicle.
Around the launch pad, there are "sacrifice" telephone poles in front of the actual poles to act as a shield to keep the real ones from burning up or melting.
The other thing @torybruno said was that it was hard to get a sense of scale. He felt it most when he went to the top. It's essentially a 30 story building.
The MOC was built to consolidate range control into one location. Prior to this, Each SLC had a blockhouse to serve as mission control for the launch. They were only 100 yards from the rocket.
The hard part is that of the VAB driver's job is that they can't see everything. Parts of the path are built at the max turning radius, which is 6° so they have to hit their marks very precisely.