The only time a parent should count is if they are counting for themselves to give them opportunity to cool down. You have trained your kid to misbehave when you count. Kids should not be given mixed signals. It is either acceptable behavior, or it is either unacceptable behavior. You have taught him that it isn't unacceptable behavior until a count of 3 is reached. Every rule can be broken.
Both you and your husband are working. My guess is that you are spending a lot of time taking care of physical needs and winding down from work. The shouting and screaming is an attempt to get your attention. He has figured out that misbehaving is more effective in getting your attention than behaving. From what you are saying, I feel you are trying your best to prepare the food and take care of the household before bedtime. You are frustrated because you would like to focus on these task and his behavior prevents this. This is when you and your husband should work together as a team. If you are cooking dinner, then someone needs to be setting the table. You husband could do it, but who ever does it needs to be getting your son involved. Have him do the things that are within his abilities. If he can carry the plates to the table the fine. If you are worred about breakage, the have him place the flatware, forks on the left and knife and spoon on the right. Napkins at each place. Salt and pepper etc. It gives him something to do. It will let him feel that he is making a contribution. It is an opportunity to have dialog with him other than a shouting screaming match. Activities such as these are an opportunity to give him praise.
Limit the contact he has with violent cartoons and shows, like the power rangers and limit the surgar intake. Kids act out what they see. When confronted with an activity they do not want to do, give them a choice. It gives them the idea they have some control. For example, if you want them to go to bed, don't ask them if they want to go to bed. Give them a choice.... Do you want to go to bed with the bunny rabbit? or do you want to go to bed with the Bear? You still get what you want and they still feel they had a choice in the matter. I can not over emphasize the importance of reading to your kids, especially at bedtime. There are lots of good children books on the market. Some are very entertaining and can be morality tales that allow you to demonstrate the behavior modification you desire. It is also one on one quality time.
Prime time TV is nice, but so is a vcr with record capabilities is better. Don't feel you are missing something on tv to spend time with your kid. A full belly and quality time, not quantity time, with your child will go a long way in addressing his insecurities. A bath and 30 minutes of bedtime stories is a nice way to end their day. It may allow you to get everyone in bed by 8 or 9 and then you and your significant other can get some quality time with each other.
This is just another opinion, one of many. Take it with a grain of salt.