[Morthoron]

Excellent post, Form. I'd add to your rep but it seems I must first spread the wealth around.

Consanguinity aside, it must be remembered that Elrond would not consent to marriage between Aragorn and Arwen until the Dunedain retrieved the rightful kingship of Isildur's line. Aragorn wasn't ever going to get the key to Arwen's chastity belt until he was crowned. This is Tolkien at his medieval best, in that a kingship was absolutely necessary to seal a deal between the two Houses (one whose rank and lineage was even greater than the other), and this is an important element of medieval thinking which persisted all the way up to Queen Victoria's progeny (and the congenital defects suffered by the ruling cousins scattered throughout Europe).

The bloodline was indeed important, but nevertheless Aragorn needed to be worthy in a real, political sense, and not just some arbitrary joining of kissing cousins.