Don't get too bogged down with this dominance thing. Very few dogs are truly dominant. This sounds like purely a matter of not having any training and a need for more socialization around the people your dog seems to have a reaction to. I would suggest a group obedience class with a trainer who uses positive methods and who has a good reputation. When you give a command, you need to make absolutely certain that you can enforce it. When you give a command and the dog blows you off, he's just learned that he can do just that.....ignore you. So, don't call the dog to "come" if you're not able to bring him to you. You need to do some active training with a long line and have some treats in your pocket. Get the dog excited and make yourself very, very interesting and fun to your dog. Run the other way and make yippeeeee skippeeee fun noises, clap your hands, hide behind something, jiggle a toy...whatever you can to entice your dog to come. When he is just a few feet from you and you're positive he's going to come, add the word, "come." Then when he gets to you, praise him lavishly and give him a few very special, out of the ordinary treats. (small) Be consistant. The same with sit, down....work on stay for very short periods at first. Praise for baby steps. Make everything you ask of him worth it to him, whatever you want him to do has to be made more interesting and exciting and rewarding than whatever has his attention at the moment. You must be able to enforce ANY command or else, don't give it.
Socialize your dog more. Get him out and about and let him see some people who he is reactive toward from a distance...not right up close and when he sees them but is not yet getting all tense, reward him, give treats. Associate these people with good things. Over some weeks, get a little closer. Ask some strangers if they'll toss your dog a treat when he sits quietly. Do not reward if he's going balistic.
You can teach your dog to "watch" you when you give the command to watch. Hold a treat by your face and when he follows his eyes up there and is looking at you, praise and give the treat. Say his name first and then "watch." Do this every day till he gets in the habit of looking at you when you tell him to.
Obedience training will make him look up to you more and respect you more. He'll know who his leader is and should settle down. Use positive methods, not harsh ones. Reward good behavior and distract from and give alternative behaviors when you don't like something he's doing. Don't give payoffs for bad behavior and don't let him self reward. For instance, when he's thinking about barking and lunging off the leash at someone, catch him before he does and tell him, "watch".....and then "sit." Keep his eyes on you if you can. Praise him for doing those things. Try to prevent him from doing the no no before he gets riled up.
Teach "leave it." That's another very useful command. He needs to leave things alone. You can set up some enticing objects in your house or in your yard and walk him past. When he shows interest in them, say, "leave it" and keep walking. When he pays attention and continues walking without trying to go for the objects, praise him and give him a good treat.
Hope some of this helps. He really doesn't sound like he's dominant to me...just needs some training and socializing. Most dogs aren't. They'd rather not be as long as you are a clear, consistant leader and a fair one and show him what you want and show him how wonderful he is to comply.
Hope some of this can be of use to you.