Okay, here is all the canon proof I have from Origins showing that a male Cousland becomes King of Ferelden. I have not played a female Cousland, so I can't say if she becomes queen or not. That is up to Meave.
The claim: The male Cousland can become King of Ferelden through his noble title of Teyrn of Highever and vote of the banns in the Landsmeet.
First issue: Can the youngest Cousland become Teyrn of Highever?
I know I wrote the Dragon Age wiki is a public blog, and that is true, but what I post now is quoted from the game's codex entries.
http://dragonage.wik...entry:_Highever
Now, this proves two things. 1. The Cousland family is second in rank only to the king. 2. If the player is the human noble, Howe cannot claim the teyrnir. If the player is anything else then Howe is named the new Teyrn of Highever. As someone who played as the male Cousland, I can confirm that my codex does indeed reflect the first option.
So this tells us that without the younger Cousland, Howe takes the title of teyrn. Only the younger Cousland's survival prevents Howe from taking the title. Fergus survives in either case, yet he cannot prevent the title from being seized.
Next is Dairren's statement. He confirms that the younger Cousland is more likely to be named teyrn than his brother Fergus. This shows that title passes to the one most capable, not necessarily the eldest.
If you do not ask Bryce if Fergus will be the next teyrn, Bryce will not name an heir. Either way, Fergus goes missing in the Korkari Wilds and is not able to fulfill the role of teyrn. In this case, the younger Cousland is the only one left to carry the title and fulfill the role.
Next issue. Can the Teyrn of Highever issue a claim to the throne?
According to Dairren, many believed that Bryce should have been king rather than Cailan. This proves the Teyrn of Highever is eligible for the throne.
Loghain also confirms this, as he tried to take the throne through his own title as Teyrn of Gwaren. This was the reason for the attack on Highever, which was supposed to wipe out all the Cousland heirs, leaving Loghain as the only teyrn.
Next issue. Is this a strong claim?
Well, that is for the banns to decide, but considering Bryce was favored by so many, it shows that many banns would prefer this claim even over a full-blood relation claim. The next question is if this claim is stronger than Alistair's and Anora's.
According to the codex entry "Politics of Ferelden", the king is essentially a teyrn. He is the most powerful teyrn. So, if the king dies, the next most powerful teyrn is the Teyrn of Highever. No one is claiming that the teyrn becomes king automatically, but in practice he becomes the main guiding power until the banns can elect a new king.
So, the most powerful teyrn in Ferelden, Maric's bastard son, or Cailan's widow?
The strength of each lies in a different type of claim. Historically, there are three types of claims. By relation to the royal family by blood or marriage, by law through noble title, or by force. Eamon brought up his and Teagan's relation to Queen Rowan who was married to Maric, but he recognized that Anora's claim through marriage to Cailan was stronger. So he suggested Alistair, who is a descendant of King Maric. Blood is thicker than water. Another option is law or title. Sophia Dryden was Arland's cousin, so she had a family tie to use as a claim, but she was also an arlessa. Whether she used this or not is unknown, but her leadership experience, as well as Arland's lack of it, was probably brought up. Sophia failed in both cases. Another example is Loghain. He tried to make a claim to the throne through his title as a teyrn. Anora can confirm that Loghain was indeed putting himself forward as a candidate for the throne. If you tell her you will not support her and ask if she will support Alistair, she says that her father must be stopped from taking the throne. The last option, using force, is the method Calanhad used. He forced the banns to swear fealty to him, and with that he united Ferelden.
http://dragonage.wik...ics_of_Ferelden
Taking each candidate on their merits, Alistair is probably the weakest. He has no ruling or leadership experience. It can be assumed he would be Eamon's puppet. Anora supposedly has fives years of ruling experience, though that can't be verified. It is said that Cailan allowed her to administrate his lands, but even if that is the case, it could be argued that she lead Ferelden into the mess it was in. Regardless, once Cailan was dead, she was swept aside easily by her father, a lesser noble below the crown. This proves her inept in matters of political force. Alistair's only edge is his alleged blood relation, which only counts for something among banns who are willing to hold to tradition and take a risk on Alistair being anything like the father whom he never even met. The Cousland on the other hand was the full-blood son of Bryce (whom many wanted to be king) and Eleanor, held the highest commanding title at the time, demonstrated leadership ability in amassing a sizable army to defeat the blight all while other nobles plotted and even tried to assassinate him multiple times, and he helped other nobles in personal ways while exposing Loghain as the cause of the conflict. He also won the duel in the Landsmeet.
The Cousland actually fulfills two of the three styles of issuing a claim, title and force. Some banns could even value the blood relation he has to the Cousland line, and hold that on par with the Theirin bloodline, though this doesn't really count toward the first type of claim.
Next issue. How is the monarch determined?
http://dragonage.wik...ry:_The_Bannorn
"No person has ever sat upon the throne of Ferelden without first winning the approval of the Bannorn."
This proves the throne is not inherited. Every new monarch must be elected by the banns. No exceptions.
So the banns can vote for whoever they want, within reason. They can't vote for a mage, or non-human, or a foreigner for example. But they can vote for other banns, or teyrns, or arls, or relatives of the last ruler.
Next issue, and last question. Can the banns elect the Cousland as king?
Yes. Proof of this is seen in the game at the Landsmeet after the duel.
There are two replies that deal with joint rule. They are slightly different depending if Loghain was killed or not. The first option is to Anora when she says the Cousland can't seriously support Alistair's claim/temper tantrum. The reply is, "Anora will be queen, and I'll rule beside her". If Loghain dies, Arl Eamon asks the Cousland as arbiter of the dispute, what is his decision, who will lead Ferelden. The Cousland's reply is, "I shall rule at Queen Anora's side, as her husband".
Both options are accepted by the banns. Both options prove joint rule between the Cousland and Anora.
The first option states Anora will be queen and the Cousland will rule beside her. A consort does not rule. A king rules, and a joint-ruling king rules beside his queen. The words "rule beside" prove that the Cousland and Anora rule on equal standing. The Cousland is not under Anora. He is not beneath her. He is not a consort or a prince.
The second option states in reply to the question "who will lead" that the Cousland shall rule at Queen Anora's side, as her husband. This, admittedly, is slightly less direct than the first quote, but it has the same theme. The difference is that this reply mentions the marriage. Still, the Cousland is confirming that he will rule, and that it will be done at Queen Anora's side. Not under her, not beneath her, not at her behest, not as her consort. As her husband.
And now, for those who find these facts not to their personal tastes, I'm sure you'll bring up that Anora called the Cousland "consort" and "prince" and so on. For those claims I counter with other examples from Anora herself.
At the post coronation ceremony, Anora introduces the Cousland as the Hero who will soon be Ferelden's king. No consort talk there. Also, if you press Anora on this at the ceremony and say you look forward to being king, she will call you prince-consort, but then admit that the title is "perhaps a technicality". She then says you and her will have to talk about the role you'll wish to play.
This all stems from Anora's desire to rule and not be shoved out of the way again. By calling you a consort, erroneously might I add, what she is trying to do is claim ruling power from you so she can make all the decisions. But I would remind everyone that what she claims about the Cousland's title means nothing. All that matters is what the Cousland stated to the banns at the Landsmeet and what they voted on. They voted to make the Cousland king, Anora queen, and for them to rule jointly.
If the Cousland asks Anora if he could get out of their marriage if he wanted to, Anora tells him that short of dying against the archdemon, probably not. This is because of what the banns agreed to. The agreement was their marriage and joint rule. That is why the Cousland can't back out of it.
So, we done here? If not, I have proof from the other Dragon Age games, including as recent as Inquisition.