In reply to some of your responses...
-I didn't know about Montalban's appearance being darkened for Space Seed. As for Wrath of Khan, the character came off enough of a person of color where it didn't seem like a whitewashing to me. It's also a good point that you noted how Nordic the refugees were for Wrath of Khan. I hadn't thought much about that before and just assumed that they were the only survivors, along with Khan. When I come to think about it...that could lead to a whole other discussion about why Meyers didn't make Khan's people diverse. At least Enterprise got it right with their casting for the Augment trilogy (even if the augments of color didn't have major roles).
But for the most part, having a guy retain his natural skin coloring is different than casting a person of a completely different race/ethnic group as was done in Into Darkness.
-I am glad that you are concerned about the whitewashing of Khan as a white person. I've read many of your posts over the years and I know that diversity in Hollywood has been an issue you've long supported. As a person of color I couldn't help but groan with a here we go again eye roll at Cumberbatch's big reveal. It gets tiresome sometimes feeling that you are incidental or less important in many of the stories that you love, that the characters who look like you (if they get cast at all) are the less developed (if developed at all), or can be more easily dispatched or possibly replaced.
-As for Uhura I don't have a problem with her relationship with Spock. It is a step up from what the character had been-as that passage you posted really showed-however I wish that so much of her character/characterization didn't revolve around Spock. His doesn't revolve around her that much. His bromance with Kirk and the loss of Vulcan, plus the eternal struggles to reconcile his Vulcan-Human halves are all interesting things they are doing with Spock that don't necessarily include or have to include Uhura. If you took away the Spock relationship, what would Uhura be doing? Who is she?
This isn't a problem that plagues just her, it's also Sulu and Chekov, maybe the new Bones as well. I don't think Uhura should or has to be single, but I wouldn't mind if they also found ways to make her more independent from Spock.