I don't have a strikeplate on the front door, so I set up a chair by the window and crack the curtains some so the dog can go to the window and snarl at them while I'm gone.
Cameras..you can get a decent camera setup for 2 or 3 hundred dollars now. You do not have to be tech savvy to run a wire! These camera systems are not complicated and easily installed by first timers. They are easier to install than a phone jack (as far as wiring goes).
Dogs..A dog is always good. Two dogs are better. Some may think about dealing with a seemingly mild tempered dog, but two dogs will egg each other on and be more aggressive than if they were a single dog. Not many people would want to take on two dogs at once. Instead they will go to your cat lover neighbors house.