Compared to other animals. Cheetahs are fast, A kiwi bird laying a massive egg relative to its body size. And some frogs being able to secret toxins as a deterrent to being eaten. Besides brain power, human beings are relatively squishy.
To add another note to the topic of skin... Sweat. A fairly efficient method to cool you off.
This is real interesting to me. Many of the things you said coincide with my anthropology class I took early in the year. And were it not for wolves, humans wouldn't have been nearly as successful. Thanks for the comment