Compare
(A) "If Anna was here, she would've known what to do."
(B) "If Anna had been here, she would've known what to do."
In (A), the speakers are currently considering what to do and lamenting that Anna isn't with them right now, because she would have been able to help them.
In (B), the speakers are discussing a past situation (we don't know how recent) where Anna's absence left them with no solution. The opportunity to do the right thing has now passed.
I think if you see the difference between the two, that will go a long way to helping you with similar constructs.
"If you (wear) a beard all the time, they (not recognize) you without it."
All the below are possible:
(A) If you wore a beard all the time, they would not recognize you without it.
(B) If you had worn a beard all the time, they would not have recognized you without it.
(C) If you were to wear a beard all the time, they would not recognize you without it.
(A) Can be used in a past sense, in a kind of confirmatory way: Given that you always wore a beard, then of course they wouldn't recognise you without it. But it can also be a suggestion for the future: if>then.
(B) In the past period referred to, he wasn't in the habit of wearing a beard, and therefore had no chance to pass unrecognised by removing it.
(C) More specific than the second sense of (A). Making a hypothetical suggestion concerning a group of people currently unknown; implying that at the moment he doesn't wear a beard all the time (or at all).
Would is the preterite (past) form of the modal verb will. It can be interpreted as future in the past, just as could indicates ability in the past. See English modal verbs | past forms.
However, in the referenced sentence, it seems that it is used to express a wish that was not fulfilled. There seems to be an implicit "if" that is omitted from the sentence. It could have been written as a conditional using the past subjunctive mood:
(If she were) to go on talking forever right there next to me, I would go on living, like that, I would be able to go on living(...)
Would can be used to express wishes, as in "would that it were true". See Use of the past subjunctive.
Best Answer
The question "What would she have said?" is a question form of the sentence "She would have said". So "has" wouldn't work here: "She would has said." ...is very incorrect.
And yes, "If he had chosen differently, how would he have turned out?" sounds quite natural and means what you want.