It seems to me that your family is not presenting a united front. You are the disciplinarian and the rest of the family is letting this little kid do whatever he wants. You need to get everyone on the same page - I suggest counseling with a child psychiatrist. He/She will give you tools to use.
In the mean time, you need to be consistent and firm. Set the rules. No screaming. If he screams, you tell him - we don't scream. We use our words. I will not get you anything until you use your words -- and then don't give in.
If he hits, put him in time out every single time. Make him do it.
He won't like it, but he will learn that YOU are the boss and that YOU ARE to be RESPECTED - without question.
If he runs away, you haul his sorry butt right back and put him in the chair. That's a safety issue. My son spent a LOT of time in time-out and has turned out pretty darned well.
As for sleeping on the couch - NO WAY!! Set a bedtime routine and stick with it. Do not deviate from the routine. Bath, stories, bed... in bed. Put the crib in his room and put him in it.
Since your husband isn't helping - you've got to do it. Remind your husband that at 2 this stuff is cute, at 6 or 7 it's awful and at 16 it's juvie!
As for the older siblings - tell them they are NOT to indulge your son and let him stand on the counters. If you see them do it, step in and take him down. Tell him we don't stand on counters.
You can do this.
Do your research - 123 Magic, Love and Logic, and any other parenting book you can get your hands on. Go to mommy groups. Find some other parents and pick their brains.
Be strong.
It will be worth it.
LBC