You did a great job.

Is there any genius or first-century scholar who believes that a person can make a halachic decision against the opinion of the rabbis if he himself is not fully barren?

An amusing question. What does "the opinion of the rabbis" mean? Which rabbis?

For example, regarding the question itself, it seems to me that the opinion of the vast majority of rabbis today, and perhaps throughout the generations, is that a simple person cannot clarify an issue for himself if he is not worthy of teaching, so I asked the rabbi if he could refer to sources that say the opposite.

That's not what you asked. But for our purposes, I didn't write that he can clarify an issue for himself if he is not a bar-hi. On the contrary, I have written several times in the past that only a bar-hi can rule for himself. But when he comes to choose the position of one rabbi or another, he can do so himself, and does not have to stick to one rabbi.

Thank you for the great clarification, can I please ask for some source from the geniuses or the first ones that says so?

This means that a simple person can choose the position of a particular rabbi throughout the generations on a particular issue.

Here I saw a summary of the issue:
http://www.halachabrura.org/dafyomi/eruvin2.htm

But how can we conclude that this is a simple person? After all, we are talking here about deciding a dispute between the poskim, and for that, one must be very wise, as you wrote in the article on autonomy in halakhah, right?

Why assume that? If you are the judge yourself, you don't have to decide anything but do what you think.

This is what I understood from sources in the Rabbi's article and more:

Geonim: "The question here is two answers from two Geonim who disagree with each other, and each of the judges or dayanim has taken one of the two, which is their servant."

Answer: The judge who is older than the time will decide, the knowledge of the one he sees with his eyes. And what he decides in his heart, if the first judge is hung up on the words of the other gaon, there is no one to look after him…”

The Chief Justice: "And if two great men disagree on a halakhic ruling, the judge should not say, 'I will rule as I please.' If he does so, this is a false judgment. Unless he is a great scholar, shrewd and reasonable, and knows how to rule according to the words of one with clear and valid evidence that he has at his disposal. And even if another scholar rules on a different matter, the scholar can contradict his words with evidence and disagree with him as I wrote above, provided he has assistance from one of the two dissenters. If not, then he will not spend enough money..."

A quote from the rabbi from the article: "The language of the Rosh means that even in the matter of deciding disputes that remain open, the sage must be 'bar hik', since the Rosh ends the above passage with the words: "And if he is not bar hik, he will not spend sufficient money," and this means that even deciding the doubts of the poskim ('spiqa darbuvata') is not given to someone who is not 'bar hik'."

The Rema (Hoshen Mishpat 25:2): "And a person should not say, 'I will do as I please' in a matter in which there is a dispute... unless he is a great scholar and knows how to decide based on evidence, the authority is in his hands, and if not, he is a barr... If he is in the teaching of prohibition and permission, and he speaks of a prohibition from the Torah, he should go to the stricter one, and if he speaks of a rabbinic one, he should go to the milder one."

If I may, please also ask what is the Rabbi's definition of the most beautiful?

They are talking about dayanim and not about poskim. There is a very big difference. The dayanim decides and his decision is binding. Furthermore, a dayanim is not supposed to decide according to his personal opinion, since there is a matter of certainty (uniformity) in the law. Therefore, from the perspective of the dayanim, he decides between existing opinions. In contrast, a poskim decides according to what he sees. He is not supposed to be bothered by the existence of different opinions, unless he himself does not have his own position. The layman cannot decide in Halacha either, but he can trust a poskim that he sees, after all, that poskim is the most righteous. The Rema, of course, does not act like me, and I wrote about this in the article. He is one of the precedents, and the entire article is dedicated to presenting a different position.
There I also briefly discussed the question of who Bar Hik is.

"The layman cannot decide even in Halacha, but he can trust a judge he sees fit, because that judge is the most righteous."

Can I please have a source that says this?

That the layman can rely on different jurists in different generations on different issues as he sees fit

I'm exhausted.

Did I ask for something illegitimate?

The rabbi says something that seems to me to contradict the position of all the rabbis of our generation and before us, up to the Talmud, from what I have encountered to date. Is it not legitimate to ask the rabbi for a source for his statement?

Or let's assume this is an innovative opinion of the rabbi, perhaps giving some Talmudic source that would indicate that it is true.

Everything is legitimate, and it is equally legitimate for me to say that it is not interesting and not important. If I advocate autonomy, it seems strange to me to demand precedents for a claim that does not need to be based on precedents. I explained that in my opinion, this is what is written in the issue itself, and that is enough.