As he hits you all, is there someone doing this to him, sometimes this is learned behavior and if Family are taking "Shots" at him how is he supposed to behave , he will copy. What does he get furious about ,what triggers the Tantrums take a look , do not feed into them when he seems upset, Back off. With the Potty training, take away the diapers and Pull ups ,get him nice big Boy underwear and talk to him about using the Big Boy Potty, if he has an accident on the Floor thats okay it part of the learning process.Remind him during the Day to use the toilet as sometimes Children become engrossed in Play and forget to go,Get some Physical activities going Boys respond well to all sports and Ball games it makes them feel good.