Yes thank you, the dwarves & ents are quite the studies in gender.

I'm not a Tolkien nerd and could easily be missing details, but am not clear that Bilbo & Frodo, for example, were pressured to marry.

Aragorn is "Half-elven"--a descendent of Beren and Lúthien whose story is narrated in the Silmarillion. I'm getting this from Verlyn Flieger's essay "Frodo and Aragorn: the Concept of the Hero."