Well, you already know my opinion as far as heavy handedness and what makes a good leader. Your dog needs to know where he stands in the family and how he comes about learning this is not by being heavily dominated, but rather by becoming a working member, earning his resources, which you control, having to follow YOUR lead and everyone else who interacts with him, not that he is acting in some way and humans are reacting. His day needs to be quite full as far as having a job, which means obedience training and commands here and there throughout the day. He can learn the give and take game with lower value items first and gradually increasing to higher value items. He needs to be conditioned heavily to having people (adults) around his food, practicing moving his bowl, as long as it is safe to do so, but first putting some goodies into his bowl so he sees that you are the provider of good things. Having him do a command or two (skill) prior to getting his food and all other things he likes will further teach him that he does not call any shots. You do. I think if you hold your child (up high) when you do some of these things, that may/may not help him see that ALL humans are controlling whether he gets something or not. But again.....I think it's a scary thing to have a little child around a dog who has bitten, even once.
If you're going to talk to trainers, these things which I've gone over should be part of his/her's program. If he/she talks about scruffing, rolling, jerking, scolding.....in other words, punishing, I'd stay clear. Punishment, IMO has no place in teaching a dog who it's leader is or how to learn manners. Good leaders are firm, assertive and see to it that rules are followed etc, but they do not get emotional or overly forceful. That's my opinion. It's how I've always handled dogs and I have no problems with behavior.
I sure hope things turn out for you. I also wouldn't wait much longer before you come up with a plan of action. The longer the dog goes along with confusion about his place, the more established this idea he has will become.
Best of all to you!