From this, and from your other definitions, it would seem to follow that the notion of biological history entailing amoeba to man evolution does not qualify as a theory. Evolutionism in general is too willing to entertain as fact what are only educated guesses.
There's no such thing as "evolutionism". Evoluiton is a grand theory, composed of a mutitude of well supported theories. The "educated guesses" are hypothesis regarding particular details. The standing of the theory of evolution itself, does not depend on any of those particular details. That holds regardless of whether, or not, there's a hypothesis connected to the particular element.
IOWs the theory applies to the set. What's known about any of the details within the set is irrelevant as far as the set's concerned, because the set is open.