Dranger, most of what you have said makes me think you're going about this properly. The thing that worries me is you saying you'll hit your kid. I'm not telling you not to, but I will say that hitting my nephews is one of my biggest regrets in life.

Read a tucking book. This is not some decision to be taken lightly. Read some scientific studies on the matter. The concensus seems to be that at best there is a short term positive behaviorial adjustment, but that comes with very serious and lasting long term negative impacts on behavior.

To echo wuf, set an example with your actions. You surely don't want your kid to default to violence and aggression to solve his problems, or maybe even worse, if it's a girl, for her to respond positively to violence from a man she loves.

Off topic: Ong, I challenge you to find one reputable study that shows positive correlation between marijuana smoking and lung cancer.