Other useful attributes of good theories:
(1) Good theories make predictions about things yet to be observed. Confirmation of predictions strengthens belief in the theory. It must be possible to determine unambiguously that a prediction is false.
(2) If two theories are equally successful in explaining a set of phenomena and predicting new observations, scientists generally prefer the simpler theory that postulates the smaller number of explanatory concepts or simpler concepts.
(3) In general, scientific observation implies the capacity to measure things. If you can't measure it, it's not real! If you can't measure it, you can't study it scientifically.
The "theory" of evolution as it exists today flunks all of the above criteria. What does it usefully predict? Is it simple? Can you measure stuff with it? No. So, while the "theory" of evolution is technically a theory (by dictionary definition), it is a pretty crappy one. It depends upon our knowledge of genetics for inheritance of characteristics...but provides no observable mechanism for the evolution of new species. Yes, it says that an "accumulation of mutations" can do the trick. Maybe. We know this works at the level of viruses. But not higher level organisms. Yes, insects can "evolve" in the sense that a species can become resistant to insecticides (because most of them die off and only the ones with the resistant genes have offspring) but this has not been shown to lead to new species. And so on.
My personal belief is that "evolution" may have occurred, but that it is/was guided evolution. That we live in a n dimensional universe where n = 10 or 11, not 3. And that our "structures" are therefore 10 or 11 dimensional. And that the guidance occurs from those other dimensions that we cannot perceive with our 5 senses. But that is just my belief and of course, not a theory.