I can definitely understand your frustration! It can be very aggravating when you can’t get your dog to do what you want. However, this has nothing to do with dominance – so there’s no need to “show him who’s boss.” In fact, dominance theory has been discredited for a long time now in the scientific behavior community, and plays no significant role at all in dog training or the treatment of behavior problems in pet dogs.
Instead, training problems like the ones you describe are generally caused by one of two things: either your dog doesn’t understand what you want, or you haven’t given him a good reason to pay attention to your cues. We address most training issues by going back to basics, and teaching the dog what to do using lots of rewards for the correct behavior. You also need to manage your dog’s environment to make sure he doesn’t get the chance to practice the unwanted behavior (like jumping on guests, or ignoring you off-leash) until he has the skills to be successful.