A thesis should be clear and backed by evidence, but it does not necessarily have to be controversial in order to be effective. It is more important that the thesis is persuasive and well-supported, rather than aiming to intentionally anger the reader.
of interest to you and your reader
A thesis statement is a statement that can be clearly stated at the beginning of an essay to tell the reader the point you are going to argue. A thesis has to be arguable and provable, hence using "arguments". It should be clearly stated to the reader so that they know what point you are trying to make and can understand your arguments.
You should generally never change your thesis, as this would promote confusion with the reader.
It should tell the reader what the essay will be about in the form of a debatable point.
The thesis is your main topic. It tells the reader what you will be writing about. Without a thesis the reader wouldn't know what your point was.
thesis
the conclusion
Yes. Your thesis can definitely present a controversial topic with all the aspect leading to its sensitivity. I suggest you take a look into a few thesis topic examples to help you understand what kind of controversial topics you can opt for. http://goo.gl/zR5vzD
The actual analysis and breakdown should be put in the appendix, but your findings should be in the main part of your thesis (linking the reader to the appendix should they require more information)
You can, it might make the reader question themselves.
A thesis statement tells the reader what the paper and/or research is about and why it was done. It should not have opinion but tell what the expected outcome will be. In the final summary you will restate the thesis and tell if you proved your thesis in your paper.
A thesis statement is a concise summary of the main point or claim of an essay, research paper, or other types of writing. It usually appears at the end of the introduction and guides the reader on what the piece of writing will be about.