edistomick, if I read your OP correctly, your home is also a place of business? If so, that is a key to your problem. Because it is a place of business, you have implicitely given permission to customers and potential customers to come onto your property. At which point, if said customer perceived they were in immenent threat of bodily harm or death, they may be within their rights to shoot the dog.
A fence is the most obvious answer, but you have ruled that out. Don't do invisible fencing, unless you are willing to wear the shock collar too. Also it doesn't stop predators from coming in to kill your dog, but it does make your dog an easy target.
If not a fence around your property, how about a large fenced in dog run? Put her in during business hours. Maybe in sight of the driveway so she can bark when customers drive up. Or fence off the sides and back of the house, so she can't get out front.
A fence is the most obvious answer, but you have ruled that out. Don't do invisible fencing, unless you are willing to wear the shock collar too. Also it doesn't stop predators from coming in to kill your dog, but it does make your dog an easy target.
If not a fence around your property, how about a large fenced in dog run? Put her in during business hours. Maybe in sight of the driveway so she can bark when customers drive up. Or fence off the sides and back of the house, so she can't get out front.