No, of course not. The theory has actually advanced quite a bit since Darwin's time. It is constantly being challenged, tested, and experimented on. And, our understanding of evolution increases all the time.
Yes, indeed it has, the problem is, the answers to this theory are becoming more detrimental to the theory than beneficial.
There is a monumental amount of empirical, verifiable evidence that confirms/supports the theory. And, there has not been any verifiable evidence that contradicts it. Evolution is a "scientific theory", not just a scientific hypothesis. A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment. Such fact-supported theories are not "guesses" but reliable accounts of the real world.