... The question was not why you study evolution or why you seek to understand, it was .... Why must you decide when you don't have all the info?
I thought I had answered that but will try to re-state it slightly differently:
I recognize that I will never have all the information, especially about historical events where it is no longer possible to investigate them by observation and experiment. One can use only records and to some extent the impact of the event that still lingers. Man made records are usually somewhat suspect. For example, if Hitler had won the war there would not be photos of concentration camps but of Jews leaving on trains of the own free will to go to Israel, etc. Thus I tend to trust more the natural records, but they can be faked like the pit-down man fake.
If I waited until I had all the information, I would not have much I could consider as true. That is why I tend to accept one plausible explanation for observables that need to be understood and explained, such as that only 22 of the 10,000 or so possible amino acids are used to construct all the life forms (at least the animal ones) - this fact alone strongly suggest that they all came from a common source. (I.e. is very consistent with evolution theory.) I do not know of any, even slightly plausible, alternative explanation. So this fact and many dozens of others with no inconsistent facts makes me think that Evolution Theory is very likely to be true and explaining the currently observable life forms.
I could, as you seem to prefer, just say: "It ain't proven beyond all possible doubt yet." However, that can be said, as bishop Berkeley did, about the "fact" that the Earth goes round the sun (because as he showed with irrefutable logic* neither Earth nor Sun need actually even exist). Faced with this dilemma (that nothing can be known with certainty) I chose the strategy I described in prior post. Namely when one explanation exists that has no inconsistencies and is much better supported by lots of different evidence than any alternative explanation I accept it as truth NOW. This seems to me to be preferable to the alternative of saying: Because I do not have all the evidence, and there are some less probably alternates which have not been shown to be impossible, I refuse to accept any explanations as true.
I admit that occasional my position / method will make a mistake and accept as true explanation something that is later shown to be false. Phlogiston is a good example, widely accepted as true explanation for heat physics, until Lord Kelvin demonstrated a flaw in that theory of heat. Despite this risk, I prefer to accept as true fact NOW all explanations that (1) have no known inconsistencies & (2) are much more plausible (probable) than any alternative. When two mutually contradictory explanations meet condition (1) and neither does significantly better than the other on condition (2) then I say the jury is still out as to which (if not both) is the true explanation.
To give an example of this: I accept the fact, determned by careful analysis of nearly a million birth to death records in the English public heath service files, that drinking tea without adding milk or cream to it does significantly increase the rate of throat cancer, but AFAIK, no one knows if this is due to thermal effects (the milk cools) or the tanic acid effects (the tanic acid attacks and binds to the milk instead of the throat tissue) so I say the cause of this effect is unknown, at present.
It is a matter of choice. There is nothing wrong with your "I don't know."? But to be consistent, you need to answer that to ALL QUESTIONS AS NOTHING IS KNOWN BEYOND ALL DOUBT, except that you are a thinking being or spirit.)
I want to understand most things NOW even if there is slight risk I will misunderstand some INSTEAD of not understand anything as all things are to some extent uncertain or not proven. E.g. I accept that the Earth does go around the sun, despite the possibility that neither Earth nor Sun can be shown to even exist beyond all doubt. I.e. Bishop Berkeley's POV cannot be shown to e false.*
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*Several dozens of people, if not hundreds, have tried and failed to find logical flaw in his strange position during the last 300 years. One, in final frustration of his failed attack with logic, refuted the Bishop's POV by kicking a stone and saying: If it does not exist, why does my toe hurt?
I have always thought very clever the bishop's explanation of why the non-existent universe appears to follow the physical laws: He said God made it USUALLY do that, so God could do miracles occasionally. If there were not laws, no regularity to the universe, then even God could not work miracles as miracles are by definition events that violate the physics laws. You should consider reading what the good bishop wrote - much more logical than Descartes, who starts with "cogito ergo sum" and about 20 pages later has "logically derived" that god had to send his son to die on the cross to save mankind for his original sins! Too few "moderns" actually read what the intellectual giants of the past, like Newton, Adam Smith, Berkeley, etc. actually wrote.
...How can "The Big Bang" theory be, in any way, plausible? It goes completely against everything that science has taught us. For something to go 'bang' there has to first BE something! What was there to go 'bang' in the first place?
Just as evolution theory is silent on the cause of the first life form so is big bang theory silent on the cause of an infinite concentration of energy. It only describes the physical evolution of that concentrated energy, how it expanded, cooled enough for matter to form, etc. why it was only hydrogen and helium and about 20 years ago why it is matter that is now observed (and not equal amount of anti-matter - that was once a flaw in the big bang theory that help make the steady state theory have equal plausibility)
SUMMARY: WHEN THERE IS ONLY ONE EXPLANATION THAT HAS NO CONTRADICTIONS AND ALL OTHERS HAVE LITTLE OR NO FACTUAL SUPPORT, THEN I ACCEPT THAT EXPLANATION AS FACT. Evolution theory is exceptionally strong now with 150 years of increasing confirming evidence, especially as there is no evidence for any alternative theory that claims to explain the observations. I choose to not adopt the position that I know nothing as I do not have all the facts yet.