Golden and aggression toward owner

Question
My Golden (Paris)is three and a half years old and not neutered. We got him when he was 8 or 9 weeks old.  We already had a cat (London) who didn't like him, but they learned to get along. In November I got another dog,(Jersey)a Maltese and from day one they hit it off.  Of course the little one tried to show who was boss and likes to bite on the Goldens ankles and ears, but he has never been aggressive toward her.  Overall he (Paris) is a great Golden.  
Last year, my god daughter must have upset the Golden and he snapped at her and scared her.  Last month, he bit her.  She said that she was was dancing with him, (she had a hold of his front paws)as he likes to do often.  According to her another little girl tried to grab his hind legs and pick him up.  We believe that because he lost his balance he snapped at her to release him.  
WELL, Last night, I (his OWNER!) tried to pull him out from under the bed, by one of his hind legs and when he came out he snapped at my hand.  Didn't break the skin, but definitely got my attention.  After he came out I scolded him for trying to bite me and went to smack him across the face, he then snapped and growled, but didn't bite.  I am soooooo upset because I feel betrayed and am terrified of him now.  I don't know if I could ever feel safe around him again....
I am afraid for my daughter who is only 8.  How do I know this will never happen again?  

Answer
No worries. I had the exact same problem when my golden Max was around 6months. Of course there is an age difference, but it just a matter of dominance. I think you need to claim who is boss and that Paris cant snap or growl at you under any curcumstances. Whenever you are ready just pull his hind legs gently and see if he gets aggressive. If he does, just firmly knock him down swiftly down and lay on top of him. Then give him a stirn commanding look and say " NO" (no need to yell it, just be clear) and growl at him. If he gets really aggressive and starts biting, close his muzzle shut tight and continue to growl at him saying no. As soon as he calms down, praise him and get off of him. If this doesnt work, feel free to email me again. Bye. Oh, and one more thing. Make sure he isnt getting mad because there is something wrong with his hips or hind legs. Maybe it hurts him when you pull and in self defense he might be protecting himself.