Dominant Golden Retreiver....HELP!

My golden has been kicked out of 2 different obediant classes. He loves the family, but he is very very fussy what friend of ours or stranger he allows around him. He is very 'ALPHA' and 100 pounds. He has a low growl he shows everyone who pets him but he still wags his tale but then he shows his teeth and he wags just until he'll attack. I do not trust him, for some reason he's 100% fine with 10% of strangers otherwise he is muzzeled. He does not let my 3 yr old son go near him , he is the BOSS! He loves my 10 yr old daughter but as soon as she sits on the floor he tries to 'mount her'. He is fixed?? He loves me but will not listen to me until I repeat, and repeat. He sleeps on the bed and refuses to move, you must walk over him he will not move. He is the BOSSSSSSS! He lays at my feet, yes I am mommy but he'll take his bum and push me while i;m walking across the room into the wall. He will cut me off! He is so DOMINANT! [B][COLOR="Blue"][COLOR="Black"][B]My biggest concern is with strangers, why is he so fussy to whom he allows in his life?? Even if he's met the same person many times he still with growl and growl while being petted? Why does he let the one in a million complete stranger pet and kiss him without even a growl? What is he thinking??? Why does he HATE small children? Is he just being protective of me? I can do anything to him he does not growl at me. Some just say he's vocal but i've seen him attack. He attacks 9 out of 10 dogs until they submit. I can;t let him run with dogs he'll kill them!! What do I need to do to help my BOY BEN????
thank you kindly,

Duplicate post. Replies given in other thread.....

http://www.pets.ca/forum/showthread.php?p=556956&posted=1#post556956

He has been kicked out of obedience classes? Have the instructors given you any suggestions or did they just give up on him? If they gave up then I don't think they were very good trainers.
You need professional help and fast before he bites or attacks someone. He is out of control and you have allowed him to rule the house. The first thing he needs to learn is that you are in control and you may need a professional teach you how to do this. Until you do get help I can suggest you look into NILF (nothing in life is free).
He should not be allowed on the furniture, should be made to sit and wait before he eats. He needs limitations and because he hasn't been given any he is in control.
You can check with your local golden retriever club for a trainer that specializes in dealing with dogs like yours. You can also ask your vet for a reference.
Are you able to contact his breeder. Perhaps he/she could recommend a trainer.
I have fostered a great many goldens and while it isn't common to see this kind of behavior it does happen. I haven't dealt with an adult like yours very often but I have had puppies who needed to be taught that humans are in charge and not the other way around.
If you can't find a trainer in your area, please feel free to IM me and I will try and help you find someone through one of my contacts.

Duplicate post. please refer to:http://www.pets.ca/forum/showthread.php?p=556956&posted=1#post556956