Question

Have a good week!
I’d be glad to ask several questions on the above topic (I know the Rabbi isn’t fond of existentialism, but these are just guiding questions).
If I understand correctly, existentialism is based on several points (which are the common thread connecting the different thinkers in this school):
A. A philosophical worldview that claims existence precedes meaning; that is, whereas philosophers until then (except perhaps Schopenhauer) tried to find what a person’s fulfillment is (religious fulfillment, rational fulfillment, or something else—for example: for Aristotle, engagement with intelligibles; for religion, observing commandments; for Kant, being moral or rational; for other thinkers, love; and so on), the existentialists would claim that a person has no fulfillment at all, but simply exists, full stop.
B. A psychological claim that the tension in a person between the fact that there really is no meaning and his thinking that he does have fulfillment gives rise to human suffering.
C. The solution to this is that a person should create meaning for himself (an autonomous fulfillment, not a heteronomous one), and in Sartre’s words, “Man is condemned to be free,” and logotherapy is based on this.
If I’m formulating this correctly, I have several questions:
1. Why does a person specifically think he has meaning when he does not, and how is this different from any animal? (There is also religious existentialism, of course, but I’m not talking about that.)
2. Insofar as they say that a person can create meaning for himself, why shouldn’t we define that as meaning that a person really does have meaning, except that only he can determine it? Why do they insist on defining him as having no meaning?
3. Can it be said that secular existentialism implies there is no free choice, since choice implies an external purpose, and therefore insofar as they claim there is no real meaning, it follows that there is no choice (but only deterministic or random choice, dependent on factors external to the person, or internal ones among the person’s own needs)?
And if I’m right, then it’s hard for me to understand how a person can choose to build his world, if he has no choice.
I know they are not necessarily committed to describing a complete worldview in every respect, and therefore they do not need to answer questions about human uniqueness and free choice—but that itself I do not understand: how is it possible to describe a worldview and not answer all of its implications? (Though admittedly this is a question one could test many philosophies with.)
Thank you very much!