He identified Goethe as a person that has overcome and disciplined himself to advance himself and "become who he is".
This rather ignores poetry was already recognised as a creative activity from time immemorial and not something then that Goethe had to invent for himself and then leave for us as a gift - he merely revived it; and the same goes for science of optics where Goethe had a special interest.
I'd also query what was he doing when he a mewling babe in his mothers arms sucking on his mothers milk. Was he 'disciplining himself' then? Or perhaps one might say, he wasn't himself yet then.
How about later, when he was a five year old, ready to go to school, and eating at the table three times a day and going to bed at regular hours - was he disciplining himself or allowing himself to be disciplined, and was he being abject in allowing himself to be disciplined? or is that question not even worth asking?
Or later still, when he is eighteen and has come of age - but by then - much of what he has become has been unconciously imbibed as the fruits of his own culture, or rather ours, as culture everywhere belongs to all, and is not the property of any one nation or a man - though it varies from people to people. There is, I think, a great deal of truth to the saying, 'the son is the father of the man'; but to be a son means to have a father, and it's the father that disciplines the son so that the son can become who he should be, which is a son of his nation; and of nations, and hence of man, himself.
He has taken steps to advance on Zarathustra's "rope tied between beast and Übermensch".
Zarathrutha, himself, I mean the real Zarathrutha, as far as we can tell said no similar thing. N merely appropriated his prophetic tone, and then not to move forward Zarathurthas philosophy, but to begat his own, which inverts and negates everything in Zarathrutha.
I find it interesting that you're confusing the character that N creates to promote himself with the real historical/religious figure that Zarathrutha was. Perhaps once it might have been seen as a 'creative confusion', but today it seems merely post-truth or even anti-truth.
the Übermensch is intimitely tied to re-evaluating traditional values and creating one's own values.
Nietschze also admired Napoleon as an ubermensch, which really suggests that N, despite all his bombastic rhetoric of coming up with a 'new ethics' and 'new values', is simply interested in asserting the ethics of the warrior. This is not new wine, but old wine, Nietschze is just bottling it into new, shiny bottles branded with his own name.
This is not a new ethics, but a very ancient ethic. All ancient traditions admitted the ethics of the warrior but they demurred placing the warrior ethic as the supreme value. Nietschze wants the warrior ethic to reign supreme. The closest approach to this in the modern era has been the frenzy of militaristic nationalism in the early part of the 20th C with the consequences that are too familiar to require repeating. This is why as a thinker and writer he has been admired by the fascistic and aesthetic set during the early 20th C, and it is important to recall this after his white-washing by Foucault and Deleuze.
I find it difficult to see why the creation of values is in any way connected to an exceptional accomplishment.
The creation of values is already an exceptional accomplishment. Its generally the creation of a culture rather than of one man, but being anthropomorphic idolaters we tend to credit a man in the singular, rather than men in the plural - or perhaps that of gods or God; it has only ever happened once. Its like the invention of the wheel or of language: it happened once, and every other so called re-invention is a modification, a renewal, or an appropriation.