Hypnosis is a bit like daydreaming. If I asked you would you reveal something from your past in a day dream your response would be 'of course not'. The same applies to hypnosis.
The media has not portrayed hypnosis in a particularly good light in this respect. Needless to say, you will not be made to act like a chook. In actual fact, you will not be made to act in anyway that you would feel embarrassing. You will not act in anyway that you don't want to act.
The answer to this question is not easy as yes or no. There have been many cases where someone has stopped smoking after one hypnotherapy session and there have been many cases where after many sessions the client continues to smoke. When it comes to your mind, there's always one person in control- you. You will decide if one session works or more are needed. Everyone is unique and every session is unique to you.
Many health funds will reimburse some or all of the consultation fees. The only way to answer this is to contact your own health fund and ask them, as they are all different.