What does Objectivism have to say about how you should act in relationships with others?
To my knowledge, the only social ethic it expounds is an application fo justice: the trader principle, the precept that one should engage in exchanges for mutual benefit. Honesty is primarily a personal ethic; its social facet is secondary. The same is true of integrity.
What does Objectivism have to offer regarding interpersonal competency? How should one treat others which one seeks to gain value from?
Perhaps if you were unevil enough to realize the level of your evilty that necessarily flows from your concious sanction of my evil, you would also realize that unevil people cannot possibly seek to gain intellectual development from an intellectual discussion with an evil-soaked intentional sanctioner of evil such as yourself.
It is because of this fundamental premise that I have heroically determined that I cannot possibly be evil for if I were to be ridden with evil I would not possibly be capable of realizing said premise. And secondly, through my ruthlessly unevil ability to be unconcrete-bound/human qua human-like, I have guiltlessly determined that your solopsistic preoccupation with the unreal and arbitrary maschinations of your mind (ie: your invisible, but nonetheless irrepressible, self-accusation that you are evil by way of sanctioning evil) renders you less than unevil, and in fact, irrational/the root of all evil.