The Landing of Elendil

[Saraphim]

Elendil, which means something along the lines of "Elf-Friend", was already friendly with Gil-Galad and the elves at Lindon. The elven-king would have probably given help by means of food and supplies, and possibly even labor.

Like you said, Osse, there would not have been very many people in the ships, but there were, like you also said, many settlers already on Middle-Earth. Most of these would have probably intermarried and thus produced many others not of purely Numenorean blood, but I do not see the Numenorean refugees being snobbish about who was allowed to settle in thier new kingdoms.

I don't think it took minutes to create the kingdoms, either. Rome wasn't built in a day, and niether was Osgiliath. It takes quite a bit of stone to make one of those cities, and there were many of them, not including Minas Anor (Tirith), which must have taken generations to create.

Thus, right from the outset, the Kingdoms of Arnor and Gondor must have not been of completely pure Numenorean blood, and the diminishing of the race must have started almost immediately!

Exactly. In the Lord of the Rings, I remember this being a dillema among the Stewards, since thier bloodline was diminishing so quickly and the amount of non-related, Numenorean-decended women for the Stewards to marry had all but disappeared. With the return of the King (no pun intented), and his marriage to one of the elder kin (notwithstanding that she wasn't technically full-blooded elf herself), this would have boosted the failing bloodline.