Here, for what it is worth, are my thoughts on Aragorn's decisions.
Now first I have to say that this is really a discussion of leadership. There are two kinds of leaders; one is a person in a position of power. The other is a leader. They are not the same. Lots of countries are governed by competent people who are really just good administrators. But if you want to win a kingdom from scratch, you've got to be a leader.
Now those ideas you brought up, honour duty, 'The Quest', sadly have nothing whatsoever to do with being a leader; only one thing matters to being a leader; that people will follow you. If you have that, all is possible. If you don't, nothing is possible.
And what is the secret to persuading people to follow you? It is believing in and knowing your men/women, to the last detail. Only then will they trust you and follow you. Only then will objectives be attainable, whether they be a beach landing or a Quest.
Napoleon said; treat your men as if they were your equals. Because they are.
The Fellowship of The Ring, the book, is a stark parable of leadership. When we first see Aragorn he is on his own. Real, natural leaders are never on their own. Frodo can't be on his own however hard he tries. So why is Aragorn on his own? On the run from his destiny? Whatever, he has to beg the hobbits to take him along.
Then we see Aragorn's first and worst leadership blunder; Frodo is wounded under his protection at Weathertop. Now make no mistake, this is Aragorn's fault. He fails to gauge his men/hobbits. He fails to be alert to the possibility of Frodo putting on the Ring. Sam sees that 'his master is in some great trouble', but not Aragorn. This is inexcusable; he is in charge of four, not four thousand. A leader should have an eye for detail and a lookout for trouble, but he has neither. He is fixated on the Quest, and ignores his men. And disaster results.
And it is a disaster. For the hobbit's sake it would have been better for Frodo to have died at Weathertop; he would have been saved so much suffering. But not for the world. If it is quests you are after, think only of Frodo.
Aragorn fails again at Amon Hen; he fails to keep Frodonear him in a time of uncertainty, or to detect Boromir's weakening, although others do, Sam and the younger hobbits, for instance>. He is blind to his men. I don't know if he mourns Boromir's fall or his death, it is a nice point. But what matters is men under his charge are harmed and die. This damages him as a leader, someone whom men may put their trust in.
It is at Amon Hen that Aragorn admits he has made mistakes. His style of leadership has failed. He vows to follow the hobbits because he has decided to cherish his companions. That is the only way he will keep men with him, Gimli and Legolas for example. Neither want to abandon Merry and Pippin. It is a popular choice, which is why Aragorn makes it. he does not make it because he wants to keep the hobbits out of Saruman's grasp, because that is an unattainable aim; the orcs are too fast and far gone to do that. It might be a side effect, but not an aim. Fan Forever puts it best, it was not his first concern.
So by the end of Book one we see Aragorn changed from a goal-fixated leader to a leader concerned with looking after his men. The way to mens votes is through their hearts. People won't throw their lives away for you for a cause; they want to feel they are being led by someone who values their lives. Then, certainly, they will risk their lives.
In book three, before the final battle some men come to Aragorn and beg to be let go home. They don't want to fight. Aragorn needs men but ets them go, with his blessing. . This is the new Aragorn, the diamatric opposite of the stuffed shirt he is at the start.
I think Tolkien is making a comment on the development of leadership in Middle Earth during the War, from the autocratic, self-destructive lemming like rush over the cliff of duty of Denethor to the give and take humane view of Aragorn at the end of the book.
Remember, all the time, in Aragorn's mind is the knowledge that however brave or strong he is, however determinedly he pursues the Quest, his success or failure is up to Frodo. That brings him down to earth. And Frodo will draw no followers to death with him, only Sam who would die rather than be cast off. It is Frodo who is the real leader.
Only musing, I used to be in uniform myself and had a real taste of leadership good and bad, and it all boils down to having a leader who in his daft way loves you; you'd jump through fire for such a leader. Soppy but true.