The main thing is producing a change in chakra nature once that's produced you can essentially learn nearly any jutsu within the element. So if learning gale palm produces the change to wind nature in theory the Uchiha gains access to all wind jutsu possible within it. The rest is down to individual skill.
My 2 pence
Well I don't think just learning a change in chakra nature allows you to access all the elemental natures by themselves, I think it requires a good sense of work and talent.
In terms of Sharingan copying, it was never really explained. For example:
> Sasuke learned his main natures "on screen": Fire was learned at the age of 6, and Lightning was taught to him by Kakashi. So he never used the Sharingan to copy anything in regards to his elements, more so when he activated his Sharingan.
> Itachi is an unknown factor, only utilizing Fire style prominently. Which we can assume he learned from his dad as well.
> Kakashi had Lightning Style before obtaining the Sharingan, he but he also uses Earth Styles (and he even used Water against Kakuzu!).
However, most of the ninjas never copied techniques, and then started randomly using the elemental natures. So I'm wondering if:
- The Sharingan just unlocks the jutsu, and the person still has to train to use the change in chakra nature
- Or does the Sharingan itself just grant access to the chakra nature once one copies the technique?
I mean this has to be explained in a data-book or something lol..
