“Don’t you get tired of this stuff after a while? “
Yes.
“Sefer Ha’ikkarim says, who disagrees with the Rambam”
So did R’Albo.
“It is extremely hard to reconcile our current way of thinking with the cures of Chazal”
See below. We don’t try to reconcile these.
“I believe we are not allowed to do any of the cures mentioned in the gemarah”
This is correct. They had been discarded in terms of refuah l’maaseh by the time of the Gaonim.
There is actually an evolution of scientific understanding as well. 850 years ago, one could have argued that the universe had always existed, or had a beginning; neither was out of bounds scientifically. (Note Rambam’s extensive treatment of this question.) Even 50 years ago this was still an admissible question. But with the discovery of the cosmic microwave background radiation in 1964 (published in 1965), that was no longer the case.
And this was an incredible example of a scientific hypothesis being tested successfully. Theoretical physicists had proven that if there HAD been a “Big Bang”, there would be background radiation all over the universe — and furthermore, the wavelength of the background radiation would indicate the age of the universe. Others had just begun to search for the background radiation when Penzias and Wilson found it by accident.