How to deal with 3 years old behaviour

[Suggestionspleaseplease]

My 3 year old is getting more and more defiant and violent and I could do with some advice. I am trying the 1-2-3 magic method but its not really working for us. For example firstly he just counts us back and tries telling us that we are going on time out (we just put him on time out anyway) secondly he will not stay in his bedroom, so we either end up holding the door handle or repeatedly putting him back, which turns into a game. We dont start the time out until he is sat on his bed, as the door handle pulling and running away is naughty behaviour. While on time out he shouts at us through the door. Silly stuff but defiant and disrespectful. He also refuses to sit on his bed, so I occasionally ask 'are you sitting on your bed?' And get back 'no, don't want to' to which I say 'you will stay in your room until you do'. He just makes up games in his room and talks to himself (not wailing), but refuses point blank to sit on his bed. He was in there for an hour today (I realise this will get me flamed) but at one point he even said 'I have locked the door and I'm staying in here' in other words he was telling me that he was in control of the situation, not me. He finally came out because he needed a poo, and only then did he sit on his bed.
We really need to get in control of this situation. At the moment it feels very much like he is in control, and I want this changed before he gets older. The hitting in particular needs to stop. I am due another child later in the year.

Any ideas? We haven't tried a reward chart yet, but think we will try that next. We do praise him regularly, offer him situations where he has some control and can choose things, and he is in general a very happy little boy, but the defiant and violent streak is really worrying me.

When does the hitting happen? You need to find ways of anticipating and preventing it in the first place (eg tired or hungry or getting more wound up). So my ds will hit me if at the height of tiredness or hunger. So I try not to let that happen. We also feed off each other when we're both tired etc and me getting cross just makes him cross (not surprising - he's just copying me!) then he ends up hitting.
So try not to go down that road.

Also time out should not be in his room. It's his room not a prison.

Let some things go. You can't do time out for everything - it loses it's effectiveness that way. So pulling a door handke wouldn't warrant time out - we ignore or remind ds firmly hit calmly not to pull the door. Your time outs sounds slightly ridiculous!

Also is he getting enough fresh air and exercise? Ds gets a bit wild if indoors too much so we take him out and run about like loons for an hour. It is also very important to have "rough house" type play with his dad eg wrestling etc etc as they have a testosterone surge around 4ish so need to get that energy out. Our preschool explained that it is best if it's a male!

I would try a reward chart. I made a 'merit' chart for my DS2 who is very stubborn and it worked better than punishing.

For good behaviour he gets to put a sticker on his chart. And he knows what the reward is when he gets enough.

Once in extreme bad behaviour I deleted one merit and he was devastated. Time out, naughty step etc - he just laughed at me. This did get his attention.

At 3 ds didn't feel bad when disciplined, he may hav cried, raged or been angry but he didn't feel bad and he didn't feel sorry. I say that because 2 years later he really does feel these things, it has taken consistent use of time out, talking it through at a level he can understand and lots of telling him how he feels and how i feel, eg 'when you called me the stupidest mummy in the world i felt very sad because i try hard to be a good mummy, i know you don't mean it because you love mummy don't you' (child has to agree)...
So hang in there and as said above only discipline when needed, it has worked, my parents are amazed at how pleasant and easy ds is now after thinking he was wild and untameable a 3