I think the way the sharigan works is that, the user can copy all techniques excluding blood line limits. However they must fill the conditions of the tecniques to use them, for example have a fire affintiy to preform a copied Fire Release: Great Fireball. So even if Kakashi can copy the Blade of Wind technique for example, he wouldn't be able to perform because he doesn't have wind affintiy. I hope that clears it up.
He can Use anything he copied, the same power, the same jutsu, and the same shape and size, he can't manipulate or develop/upgrade/Enhance ( however you wanna put it ) any jutsu that he doesn't have an affinity to. an Example is when him and Zabuza Fought, Kakashi did the same exact water dragon Jutsu as Zabuza, his affinity is Lightning only ( I think )
In essence Kakashi has all of the elements as his disposal ONLY if he has copied the technique before. If he has not copied i.e. a wind technique he cannot use wind element. Therefore he could potentially be a master of all elements, but at the same time not. He cannot manipulate or augment copied techniques. If he copied only one earth technique, then that's all the earth element he can use ect...