I cannot comment on the beeping, nor the ability to turn the system off however, both issues just don't seem logical. Did you ask the salesman? Call the manufacture?
Also, I think you might be missing a few Pro's. It's not designed just to slow you down when you approach another vehicle, it can actually be set to a distance of your choice to follow another for increased MPG.
And depending on your age, you may want to think resale on a purchase of this type. It might matter to the next guy.
For me, I would most definitely want it in any car/truck/RV at this point on.