I hate to say it, because I think I'd be the same way with a pup from a puppy mill situation... but the problem that happens with these dogs is that they get babied and spoiled because of the situation they came from. But that's not really how dogs minds think, that's how we as humans think. Dogs live in the PRESENT, not the past nor the future. So you need to start treating him like you would any other pup, giving him rules and boundaries, exercise, discipline and THEN affection (as the Dog whisperer states) It is AWESOME that you rescued him... and he knows it. But you cannot live in the past. The past is over with. He's in a great home with you, he's getting love, he's living a great life! There's no reason to live in the past. I would recommend starting training NOW before you get an out of control dog on your hands. However, he's so young that all puppies go through those phases. But obedience is very important to have a good enjoyable dog to be around. He cannot rule the house... that's your job. Take the weight off of his shoulders of being the "dominant" one. That's your job
Don't give him too much freedom too quick. I don't mean crating him but only give him access to one room in the house. When you take him outside, put him on a leash. That's the only guaranteed way you're going to get him back inside to listen to you. Use a flexi leash to give him room to run still. You can teach the come command this way. Start inside by having a treat and saying "come!" Teach him that "come" means a good thing. Then you can start the training outside. Just a flexi leash so he doesn't run the opposite way and you can give him a quick tug to help guide him!