You are mixing numerous subjects.
First, the "Buck Stops Here". That's the job, as least as it is set up in the 21st Century. President's don't go to Congress anymore to go to war or do many things. He has the best information in the world and access to the world. They control military, economy, social, health, science, interior, energy and all are policies they have to decide. So, yes. We do expect them to make decisions on things they know nothing about, everyday.
Second, Fauci was not asked science or medical questions by Paul. It was a political stunt to drag the guy into the media and read his personal diary publicly. He already has a pardon, just like most everyone else involved has no liability clauses or direct pardons. There is no reason for him to go against legal advice and answer anything about personal writings that are normally protected. This was a witch hunt meant as a grandstand by Paul. You would do the same thing, why? Because you counsel would have told you to. And only stupid people go against their legal advice.
Third, nothing the guy advised the President was contrary or different than the rest of the world. We didn't do anything out in left field, everyone else was in the same position. Doing the same things. You guys act like he was doing something different.
Finally, he did have anything to do with the vaccines. He received nothing from Moderna or Pfizer. Warp Speed was Trump's idea. Look into it, Fauci stressed the need for vigorous clinical trials. Trump pushed to skip them or redice the time. "Never been done before faster"...
Fauci's biggest crime is liking the lime light and being very unlikable. As for the "awards", that I don't know about and it was not part of COVID. They should investigate that separately, to determine if anything illegal was done. It is 4 months before elections, now is a good time for grandstanding.