Yeah, Lúthien claims that multiple partnerships would be relevant to more people than same-sex options, might easily be true.
Which doesn't affect what I'd consider the ideal end state but might affect prioritization.
I don't have exact statistics for either population on hand but that seems likely. And people who like both to a more evenhanded extent than I and would find it irritating to have to quash half their potentiality.
I'm an outlier, actually. Not the most extreme one I know, but still.
Yeah, Quendi average will probably be lower - although I assume you couldn't pursue anybody openly, which may affect what counts as "easy".
Plenty. Some species manage to be more obligate monogamous and/or heterosexual than you guys have pulled off under divine command; or only one sex has multiple partners; or having children requires at least six people and casual sex is only fun if you can get together at least ten...
You've got reasons not to go openly, there's reasons he can't get generic permission for unspecified Noldo guests such that I could disguise you as someone else, I've got reasons not to just bring you in invisibly... It's frustrating.