Science is not a profession, it is a method, an algorithm. An orderly set of instructions which when correctly applied yield the best possible approximation to a reliable and repeatable truth. It will also yield the degree of certitude of that truth as well as the degree of likely variance.
Science does not answer the question “What course should we take?” Science answers the question “If we take thus and such a course, what is the range of possible outcomes, and what is the probability of any given outcome?” There are many areas that science has no tools to tackle, which means that it is not the right method of approaching that problem. This is not a weakness of science any more than it is a weakness of a hammer that it cannot cut a straight line.
The process goes something like this. You have a flash of inspiration. You figure out ways of testing it by trying to disprove it. You try to eliminate all the other possible causes that could account for your results. You try it under as many different conditions as you can think of.
Only when you have thoroughly tested the limits of your hypothesis can you justify any confidence in it. Then comes the real test. In order to pass scientific muster you must show how you arrived at your conclusion in sufficient detail to allow others to replicate your findings. If a significant proportion of them succeed in doing so, then and only then can you claim to have arrived at a verifiable truth.
You can be an inventor without being a scientist; as long as what you invent works well enough to be beneficial in the world you can even get rich that way. You can make scientific discoveries with out being a scientist, but someone will have to do the science to prove it, it does not have to be the discoverer. The vast majority of scientists never discover anything new or propose an original hypothesis, they dedicate their lives to testing the ideas of others. Sometimes they are motivated by the desire to find mistakes in accepted hypotheses. No matter, they are all valuable to the project of Science itself, which is the search for ever more reliable truth.
Pure science barely exists in the world today. So much is known about the nature of the physical world at such a deep level, that advancing the frontiers of knowledge involves prolonged immersion on the subject even to understand the remaining problems, and then very expensive gadgets like CERN to test their theories. The days of hobbyist scientists discovering new materials are long gone, and such research is now done by corporations for their own use and profit. They are not specifically interested in advancing knowledge, but in making money. If they can make more money by suppressing knowledge, they will happily do so.
Science has among its practitioners a certain number of liars, a certain number of fools, honestly deluded people and some outright criminals. This statement could be said equally truthfully of lawyers, bankers, mechanics, wealthy people and pretty much anyone else. These are categories that people in general fall into in similar proportions throughout the population regardless of what station in life they occupy. The vast majority of people are honest and well intentioned. There is absolutely no reason to suppose that scientists have a greater propensity for dishonesty than the general public.