And wait--are you saying scientists avoid asking certain questions because of social pressure? Because that sounds an awful lot like bias. In fact, it sounds like the kind of thing for which Carl Sagan would warn people to tune up their baloney detectors.
Also, I note that the article you linked to failed to cite the numbers on the handedness and birth order studies, but I have heard these are actually rather low. Additionally, so far as I am aware, handedness is still not a completely understood phenomena either, meaning handedness studies don't yet prove something to be inborn. (If you have some data that handedness is definitely inborn and genetic in particular, it might be useful to post it.)
Regarding homosexual animals, I suggest several things. First, note the OP, which says, quite prominently, "The penguins can't help you." Second, I'd like you to consider this post, where I go through reasons why one study on rats provides much less evidence for pro-gay people than many of them think. Third, I'd like you to point out information about animals that were undoubtedly born gay. I've heard about plenty of cases where all we know about the animal is "it's gay right now." In fact, I've even heard of some who turned gay!