I don't have a problem with the Spock/Saavik thing. I mean Sarek was likely 60 and Amanda likely in her 20s when they got together. And as far as Spock being Saavik's mentor, well, I work in academia and I see marriages between professors and their students all the time. It is likely, too, that if that much time passed, we are talking about a 60 year old Saavik and a 100 year old Spock. It's not like Saavik would be a child anymore.