In light of the recent decision on gay marriage, it would be interesting to discuss what kind of marriage rights would be granted with intelligent aliens in the mix. There are bound to be people out there who would want to marry an Andalite or a Hork-Bajir. (Yeerks and Taxxons in nothlit morphs would probably be out of the question).
Would a modern day Aldrea and Dak be allowed to marry? A marriage between either race and a Human? With Andalites, I think they're too proud to marry a Human (unless they're like Elfangor). With Hork-Bajir, it would probably be frowned upon because of the Hork-Bajir monogamous nature and the Human habit of divorce.
As for rights in general, I cover that quite heavily in my fanfics *wink wink!*