Every "fact" we have is a working hypothesis, to some degree. We will call it a fact when it is beyond reasonable doubt; when the hypothesis has been rigorously tested, but it is really a semantic game. Like you said, every fact is open to revision or rebuttal but it is usually so well supported that in order to progress knowledge, we take it as a given. A theory will encompass hundreds, thousands or more hypotheses and facts, each with their own set of assumptions and levels of evidence. All open to revision. Altering one hypothesis contained in a theory does not make the theory weaker, but instead stronger because it better fits the data. It becomes more explanatory. A strong theory is one that best adapts to new evidence.
A theory will not become a law. The theory of evolution will never become a "law." It is too broad. (Most) Laws tend to be quantitative/mathematical based for the reason stated, they work best in a closed system. I say most because I am trying to think of a counter example (which I am sure is out there) but one does not come to mind. I work mainly in the biological sciences so that is where my biases rest, I am sure other fields have something to say.