Well, I haven't done the reading test, but the text looks fine to me.
My overall comment is that apart from a few minor errors, it seems a valid test. Your question was about native speakers and the test. Well, IF they know the format, and have a reasonable understanding of what examiners expect, and can spell, they SHOULD pass the test. THEY WOULD HAVE NO TROUBLE AT ALL IF THEY WERE TELLING YOU ABOUT THE QUEEN AND HER FORMER RESIDENCES. They would happily change tense and and tell you where she HAD BEEN. HAS BEEN, WAS GOING TO BE, and all that.
The problem is that many native speakers are LAZY when it comes to grammar, and get into bad habits, or have ways of saying things that are very regional, or are trendy!
SO, many native speakers would get a lot of it wrong, I'm sure. But that does not mean they can't speak English! They are PERFECT speakers of English, but they do it their way! And maybe they can't spell! And maybe they hate exams.
YOUR job is to ATTAIN grammatically correct English, and pass exams to PROVE you can speak English. Most English, Canadians, Scots, Americans, Australians, Welsh, Irish etc. don't have to bother very much. So their attitude is very different. Most of us will NEVER be asked if we know the difference between the past perfect and the present perfect. We just go by the SOUND of the words.
Back to the test: you will no doubt have found it tricky. But it is a valid test, and will sort out a good C2 from a struggling C1.
Get hold of some PROFICIENCY course books. You'll find very similar material in them.