The historical inaccuracies. OK, I'm a fan of historical fiction, I know there's always departures from history for the sake of the plot, and that's even more true when talking about one-hour dramas or two-hour films instead of a novel. But the least they could try to do is keep track of their changes! I understood why they made Margaret (whose story actually fits Henry's sister Mary) marry the King of Portugal; they needed her historical husband to be dead already so Henry and Francis could have their meeting. Fair enough. But, they should have done a proper switch and mentioned in passing that there was another sister (Mary, perhaps?) who married the Scottish King, since in season 3, the King of Scotland is suddenly Henry's nephew. In season 4, he's just "cousin", which may not denote a blood tie since it was common for royals to refer to each other in familiar terms, but still. Then there's the changing titles of Mary and Elizabeth. They were both known consistently as "Lady" after they were declared illegitimate, but the show jumps back and forth between "Lady" and "Princess" for apparently no reason.
Why are there no functional marriages? All right, with Henry and his wives, there won't be, but his love life's not the only one we see on the show. Charles Brandon and his historical Tudor wife, Mary, seem to have been happy together. Margaret and Brandon, on the other hand, have a relationship that is initially fueled on what appears to be hate sex, and then Brandon starts his old playboy ways again. Speaking of Brandon, his second wife was never estranged from him, unlike in the show. But that. at least, had a plot reason to it, showing what loyalty to Henry costs Brandon. Then there's Edward and Anne Seymour... OK, where did they get the idea that Anne Stanhope was a slut? It was Edward's first wife, Catherine Filiol, who had an affair (with his father, which is probably where the Anne/Thomas Seymour in season 4 comes from). Even worse, there seems to be no plot reason for any of it, especially the Anne/Thomas, which was completely random. The bit with Surrey is the only part that's even mildly accurate, since Surrey does seem to have had a thing for Anne for a while. But Edward and Anne - like Brandon and Mary - were a happy pair in history (they had ten kids, so clearly...) but in the show they hate each other. The only healthy relationships seem to be the brief glimpses into Cardinal Wolsey's relationship with his mistress, Joan, or Brandon and his mistress, Brigitte.
Why do they cast people who are only attractive by today's standard? The king looks like a glamourpuss, he's wearing so much make-up and the women are skinny models.
The people in charge believe the only way to get good ratings is to appeal to society's current aesthetic tastes. That and throw in a lot of sex and gore. Whether that belief is correct or not depends on how high or low your opinion of society is.
It does kind of make sense to cast people who are good looking by modern standards as characters who were considered attractive during their time period, in order to make it feel more real for the audience. Cast someone who was considered good looking by 16th century standards, and people will just see it as Informed Attractiveness. Historical pieces often modernize other elements for similar reasons. As far as having everyone be good looking... well, that's an issue with basically every show on TV, as well as every movie, comic book, video game, etc., with very few exceptions.
Plus, King Henry VIII was quite handsome in his younger years. It was only after a severe leg injury that prevented him from playing sports that he turned into the morbidly obese man who's portraits people are familiar with.
Why do they switch between calling Prince Edward "Your Highness" and "Your Grace"? I mean, historically—at least going by Shakespeare—"Majesty" and "Grace" and "Highness" were all used for the sovereign, and everyone else was just "my lord," but it seemed like they were following basically modern styles, with the King being "Majesty" and the princesses being "Highness" and the dukes "Grace." I can understand why—it's probably less confusing for modern audiences—but why did they make Edward "Grace"? And then change their minds and make him "Highness"?
Edward VI became Duke of Cornwall at his christening, as mentioned in the show. This explains him being "your Grace." Presumably his address changed to "Highness" only after he became Prince of Wales, but this wasn't shown on-screen. (This actually mimics the real life procedure for the English heir apparent, who receives the Dukedom automatically but has to be created Prince of Wales by the monarch.)
Also, traditionally (as in prior to Henry VIII), "Your Grace" had been reserved for royalty, not nobility. Henry VIII requested (and his requests were always honored) that he, as King, be addressed as "Your Majesty" exclusively. The Prince of Wales and son of the King would still be styled "Your Grace" in that era. It's a small point, but a cogent one.
This isn't the fault of the producers, but why is everybody named Thomas? Thomas Cromwell, Thomas Tallis, Thomas Boelyn, Thomas More, Thomas Wolsey, Thomas Wyatt, etc. I'm sure I've forgotten more than half of them. I know they can't change peoples names; I just find it odd that so MANY people were named Thomas.
There weren't very many first names in use in England at the time. Even as late as the 18th century, a quarter of all English men were named John.
Mainly due to Thomas Becket being the patron saint of London.
More curiosity regarding behind-the-scenes rather than the show itself: if Henry Czerny/Duke of Norfolk was such an important character, why didn't they just recast the role?
The same goes for Archbishop Cranmer (Hans Matheson), as he played an important role in the events of seasons 3 & 4.
It's especially strange as the show had no problem recasting Jane Seymour.
They couldn't really write her character out of the show, from a historical perspective...
If I recall correctly, Jane Seymour was only in one or two scenes at the very end of one season before being cast for the next. I didn't even notice this the first time I watched it. On the other hand, recasting characters with as much prior screen time as Norfolk and Cranmer would have been very jarring in this kind of polished costume drama.
More jarring than rewriting history and promoting other minor existing, or inventing completely new characters to play 'Biff the Understudy' to Norfolk and Cranmer?
Yes. Because the rewriting of the history would be only noticed by those vewers, who know history, while the recast would be obvious to everyone who watches the show.