@RallyChris is right (as always)

I suspect you may be working with a Base Map, even if the roads are named, so this link may be useful:

http://www.waze.com/wiki/index.php/Deal ... amed_roads

And if you want help, have a look here:
http://www.waze.com/forum/viewforum.php?f=142

In my experience, parking lot roads are most useful for simply keeping traffic reports from showing up on the public roads in the area. Like if there is a mall or major shopping center that sees a lot of traffic, without parking lot roads people visiting the shops there may very likely snap to the public road and have their slow crawl through the parking lot applied to the public road. Besides false traffic reports it will also result in slower average speeds for those segments.

Actually in a few places where I have defined a landmark, having parking lot roads leading "into" the landmark makes routing to that destination much better. Although you can define auto entrance and exit for a landmark, I haven't seen that actually do anything.

As for your question on addresses, I am not sure how that would work unless you name the parking lot road "Main St" also, BUT I think that would cause problems. Now if a shopping area had a name and its own numbering system (such as "Southgate Center Suite #3"), then you could name the road with the name of the complex. But that is only useful if the business advertises its location in that format.

I have another example of a use for parking lot roads. I just dealt with a map error report from a user. They were navigating to a local store, using Google results I assume. The store is located in a shopping center which is between the interstate highway and a major state highway. The entrance to the center is off of the state highway and the store building is backed up against the interstate. The Google result GPS coordinates are accurate to the entrance of the store building itself. Since no parking lot roads were defined, Waze saw the Interstate was the closest road to the building and routed the user there. Not too helpful