"Talent" is usually a catch-all for innate features distinct from trained features. ("Body shape" has both innate and trained elements.)

You said

>The major difficulty with the idea of "natural talent" is that every time someone points to a skill/whatever and says, "this is natural talent" someone else finds a way to teach that skill.

Can anyone be trained to run as fast as Bolt or would they have to be naturally talented in the first place to be trainable?