How you administer time outs and taking away things is even more important than doing it. Do you immediately respond when he misbehaves?
First set him up for success. He's over hyper so do you stop him, hold onto his hand or shoulder, and look him directly in the eyes when you tell him to do or not do something? Talking to him across the room does not get his attention.
When he back talks, do you immediately tell him that is inappropriate and ask for an apology each and every time? My grandkids do not respond to time outs. Never have. So we send them to their rooms until they're able to come out, apologize, and do what we asked. It really doesn't matter that they have toys with which to play. The idea is to separate them from their negative behavior, give them a chance to regroup and comply.
Have you trained him not to hit by taking hold of his hand while telling him "we do not hit. Use your words, I'm angry." and then if they hit again, give him a time out or send him to his room.
This is a lesson that has to be repeated over and over. Actually, teaching him to behave is on ongoing process. He will never, as a child, always listen and obey. We have to immediately and consistently give consequences after first teaching them the appropriate way to behave.
Remember he is new to this world, his brain and body are a little bit more mature so he understands a LITTLE bit better now than he did at 2. He's discovered that he does have some power. It's up to us to show him how to use his power which means giving him choices when we can. We can even say, you can choose to pick up your toys now or sit in the time out chair for 3 minutes. Then enforce his choice.
Do these things calmly, without anger or frustration, as much as possible. When we get angry and yell or use an angry tone of voice, the issue becomes emotional which makes learning difficult.
When you take things away be sure that taking the thing away is related to the misbehavior. If he doesn't pick up his toys, then you pick them up and they go away for a specific period of time. Or if he throws a toy, it goes away. But if he's back talking, don't take away a toy. The two are not related. He only learns that you take away toys. He doesn't learn how to behave.
I highly recommend books with Love and Logic in the title. They're written by Foster Cline. I also recommend 1,2,3 Magic.
Potty training may be causing some of this. How are you training him? Do you and/or him get frustrated, intense over making sure he gets to the potty on time or that he never have an accident? Is he actually ready for potty training? Many 3 year olds, especially boys, aren't ready by 3.
Parenting a child takes a lot of personal one on one attention. We cannot expect a 3 yo to immediately drop what he's doing, listen, and comply. We have to get his attention and see that he follows thru. We have to give consistent and immediate consequences when he doesn't behave. If he's not listening, we have to get his attention. If he out and out refuses we need to guide him into doing it. It helps to be involved with him to get him started in doing what we ask. We cannot say, go brush your teeth or go pick up your toys and expect him to do it without some help from us.