I am a practicing Christian and a studied theologian (3 years college) so I do have personal beliefs but I will try and make this as least biased as possible. 
 
Sarah: 
Is it possible to be cursed on Tuesdays? Maybe. 
Is it possible to decide something in your mind and ignore all other options? Happens all the time. 
Are psychics real? Some probably are, and there are likely alot of fakes (I think it's a very profitable business). 
I know of a certain wealthy Hollywood mom, who is related to a friend of mine (sister), who is a regular customer of a psychic. At one point my friend found it necessary to call the psychic and insist that the psychic give her sister certain recommendations. It worked. Her sister had gotten to a point where she could not make decisions for herself and had put complete faith, not in the people close to her, but in a well paid psychic. 
I like what Sarah said about the light. Most of the time when an individual is experiencing something, the light is brighter to them because they are closer to it, meaning they have two directions that they can take; 1) move towards the light, it will become bigger and brighter and nothing else will help. (This is what Sarah had been doing -focusing all her attention on that one thing, the 'Cursed Tuesday').It will take over your thought process and your ability to see things in life at the proper proportions and in the right perspective, or, 2) move away from the light. Try and take yourself out of the situation for a moment and look into it from the outside. Usually it becomes significantly smaller than you originally thought. In most cases this gives the person the ability to see everything else around them and helps to restore a healthy balance to their life. 
 
Advice: Focus on Wednesdays -maybe this could be your miracle day! 
 
George: 
To his credit, I do think there are some preatty crazy things that go on in different countries that we are not altogether privy to in North America. In South America and Africa there are such people as Witch Doctor's who practice a variety of things that we would lable as being on the 'Dark Side'. Whether or not a hex or curse was placed on George, I think, is impossible to diagnose. One thing I am certain of is that George has moved towards the light, like Sarah, attributing such things as a leaky roof to the curse. 
I think if Dr. Phil had asked the audience that day, there probably would have been someone else there that would have had bad experiences at the same frequency as George, maybe not with driving but something else. 
My first new car has had tire problems. In the first 20,000 miles I had a tire blow on the highway travelling at over 60 miles per hour and had a leak in another that had to be replaced. As well, you could say I have a parking lot/ driveway curse. Three weeks after getting the car another car was backing out of a shared driveway and scraped my car causing over 500$ damage. Less than two months later, I collided with another car that stopped behind me as I was backing out of my parking space. Within three months of that incident another neighbor hit my car backing out of an adjoining driveway causing approx. 1000$ damage. I don't think I'm cursed though. It's bad luck yes but it's life. I have better luck in other areas I'm sure. 
 
Advice: Let your girlfriend drive........ or ride the bus if you need to, but don't let it ruin your life bro. 
 
Sharon: 
I agree with Doctor Phil - Sweet Spirit 
Trauma as a kid is a horrible thing. 
Being an individual with a Christian background and extensive theological study I am aware of certain things about the situation. 
As a Christian I do believe in both good and evil spirits, possession, exorcism (of sorts), etc... 
I believe that spirits are just as real as humans, but being invisible the majority of the time, are often not thought of or belived in, and thus they do what they do without much interference by humans. It is not crazy to believe in spirits or possession as most of the world believes in them, except North America where a large portion of society is turning into humanists.  
As far as exorcism is concerned - as with everything - don't believe everything you see on TV. Hollywood is there to make money, not to instruct you. Some of it may be real, but reality with a small twist is what we pay to watch right? 
Without attempting to point fingers or scar thoughts of people, it is a historical fact that many have split from main stream Christianity and gone overboard with 'Spiritism". In fact I think we have gone from one end of the spectrum to the other. Being from the Pentecostal background myself I know that approxiamtely fifty years ago there was a major focus on spiritism. People would apparently see spirits in everything including walls and pews in chuirchs. Some were going as far as to tell saints whom the Lord had told them they should marry. Many people went overboard. The Pentecostals did succeed in curbing this issue but brought it back to a point where any talk of spiritism is frowned upon and rejected. 
Saying all this: 
I do not know whether or not Sharon was or is possessed. 
Yes, she made some wrong decisions but was that Spirit possession, Spirit Oppression, Lack of personal knowledge and/or wisdom, or a weakness in her. 
Spirit oppression: Usually comes in the form of mental and health related attacks that wear down a person and make them more vulnerable. 
Lack of knowledge and wisdom: She was young when she first got pregnant and from the sound of it, did not have a very good support system. In alot of cases where support is limited, bad decisions are made again and again until the individual is helped or eventually learns on their own. 
Weakness: We all have them. North Americans have a big one when it comes to sexuality. 
 
Advice: As with Doc Phil.. find a church that will help you through and overcome this issue. And since you seem like a genuine person that has deep roots in Christianity, develop your personal relationship with God, meaning that even though people can help you with the issues, your own belief and trust in God can not come through them but directly from him (God). Prayer can help and as far as the understanding of spirits and exorcism; people have made up their own ideas of these things - go to the source, The Bible. It will help you understand what is real and what is not. If you get a counsellor it is probably a good idea to get a christian counsellor since a non-christian counsellor will have different morals and values than you are accustomed to. 
 
Holly: 
Obviously the dreams are real. The question is what is causing them. Does she believe in spiritual powers (oppression, possession) or is it something only from compressed memories somewhere in her mind resulting from horror movies etc...? 
In the end if it is memories then it can go either way. If it is spirit powers then she needs to ask what, if any, is her belief in the supernatural. If she decides that it is spirits the best thing to do is follow the advice given to sharon. 
I don't know about the mirrors, candles, etc.. it sounds like it may work from the professionals (if it is memories causing the dreams). If it is spiritual, they will not work. Try them (candles, mirrors, etc...)! You'll soon find out whether or not they work. If it is in your mind then all you need to do is put enough faith in the fact that it will fix the problem and voila! From a spiritual perspective try sleeping with a bible (I've done it). 
 
Advice: First decide what your beliefs are. This will help you take the right direction. 
 
Nathan