This behavior may be normal some of the time, but not all of the time. I would talk to his pediatrician about it as well as the school system. I have a son who has Asperger's Syndrome along with Sensory Integration Disorder and he had a lot of those traits at 5 years of age. He is now 9 years old and he still has meltdowns every once in a while. I get the response "I hate you!" only once every 2 to 3 weeks now thank goodness.
I would also agree with those who told you to redirect and not tell him to just stop the behavior. He needs to know how you want him to act. Just telling him not to do it will just frustrate him because he won't know what he can do instead. Another thing is to get him into a good Martial Arts program. This has helped my son greatly with his behavior as well. I started him in this at 5 years old and the therapists have said it is a wonderful thing for him.
Well, that is all I have for now!!