How would YOU define gender a-typical behavior – in humans and other animals – will gender atypical behavior in some animals really mean anything for humans. Will it have anything to say about sexual orientation in general.

Yes, gender nonconformism is the strongest predicting factor for homosexuality, at least that’s what major researchers have found to correlate most strongly with a future developing same-sex orientation. There are a number of scales researchers use to assess their subjects’ preference of toys, games, preferred peers and so on. One of these scales even measures levels of aggressiveness. By comparison, most children are found to prefer some toys, games and peers — and these are considered gender-typical. I have read at least one scientific paper that linked toy preference with levels of aggressiveness. So we can expect that somewhere hormones played a part to later affect physical preferences, both in objects, playing partners and type of activities.
As I explained earlier, human aggressiveness can be culturally modulated in humans, but it’s the same animal instinct differently expressed. We did not create new instincts or emotions that differentiate us from other mammals, we just developed ways to channel those instincts in a lot more ways than all animals. We are masters of discriminating between states, of evaluating possible future consequences of our behaviour and so on, but we did not build any new emotion in our limbic system that was not already there in other mammalians. Can you argue that due to the specificity of human evolutionary selection we ended up with very different outcomes in sexual orientation distribution than other animals? How could non-reproductive sexual orientations survive against so many odds?