Vacuum Hissing Common?
 

Right near the firewall to the left of the fusebox (standing in front of the car) and right basically on top of mast. cyl, there are some vacuum lines, with a connector that splits the lines, etc--another which runs to a rubber thing with only one line going into it--I can hear vac hissing in this area. Normal? What are these lines for, the cruise control? (Which works fine, by the way)

No, not normal at all. trace the sound and replace
hoses or connectors.