Sufficient that Copernicus’ theory could be given an instrumental reading, as a useful mathematical tool for predicting planetary motions rather than a literal description of the motions of the planets. It did not take very much. It did not take very much. There are only a handful of passages in the original version that imply otherwise, and most of Copernicus’s readers already understood him in this way anyway. (It was quite traditional to read, and write, mathematical astronomy in this way. Geocentric mathematical astronomy generally presented itself as a mere instrumental mathematical tool also, rather than a literal physical description. They thought the Sun really went round the Earth, yes, but they didn’t mostly think all the epicycles and things were real. Incidentally, Copernicus’ theory was full of epicycles too. Until Kepler came up with ellipses, it was the only way to bring teh theory into line with actual measurement.)
No it fucking well isn’t! Get a clue. It means, for practical purposes, someone who has a degree in history or history of science, and who holds a post in such a subject at a university. (That is a sufficient, but not a necessary condition. I am sure there are some well informed histories of the Galileo affair written by non-academics. Actually almost any book or article that bothers at all about historical fact and evidence, will tell you the same thing.)
Now why don’t you go find and read one of the many books (or even articles) about Galileo written by such people and actually educate yourself about this topic that you so like to ignorantly bloviate about.
For a while, and at the time of his trial, heliocentrism, construed as literal, physical truth, was considered “formally heretical”. Note also, however, that it was not until 16 years after it was so ruled, and after Galileo had indulged in significant further provocations, that he was actually put on trial. Even after having been pushed into ruling it “formally” heretical, the powers that were in the Church really did not much care about the issue, and it is pretty clear that when Galileo did make his further provocations he did so in the confident expectations that this ruling would be ignored or reversed. He thought (and had some pretty good reasons to think) that pope Urban was actually on his side.
In any case, the doctrine that heliocentrism is heretical did not last very long. At the time of Galileo’s trial the case for heliocentrism was still very weak (despite Galileo’s own contributions to it), and very few astronomers (perhaps no-one but Galileo and Kepler) actually fully accepted it. However, in a generation or so, due to the further work of people such as Kepler and Newton, the evidence was overwhelming, the scientific consensus was solid, and the Church had to reverse itself. I do not know the exact date when that happened, but it can’t have been all that long.