As I've written on this before, I'll repost what I wrote in the past. The sum of it is that HITLER IS DEAD, and I don't just mean because he would be 127 right now if he wasn't...

One of the most common "claims" right now is the purported FBI document that seems to state he was alive at the time. But anyone claiming this hasn't read it. Anyone who had would be aware that it isn't documentation of Hitler's survival, but rather it is what some might term "the crank file". The document is perfectly legitimate, but it is a collection of a number of different rumors and tips sent to the FBI by people who thought he was alive, most of which would be quite contradictory if you were to read them, some of which the FBI did investigate, and none of which panned out. Frankly, I think the simplest rebuttal is that if Hitler's survival is a big secret, why are these documents published by the FBI on a webpage with the address "https://vault.fbi.gov/adolf-hitler/"? I would venture mainly because they are so silly and not believable. See /u/Bernardito's post which goes into more detail on this document.

As for proof in the other direction, that Hitler did actually die in the bunker, well, another popular story - which you mention here - revolves around the skull purported to have belonged to him. It was recovered by the Russians with a bullet-hole in it, and held up to have been his. It was proven a few years ago to have been female though! So unless Hitler was hiding a really big secret, it clearly isn't his... You'll occasionally see this fact circulated as proof he didn't die in the bunker, but it leaves out a rather important part of the story. The skull piece was recovered in 1946 by a team searching around the area where Hitler's remains were cremated, about a year after his death. There was never any actual conclusive reason to support the belief it was his aside from general location and a bullet-hole. The skull fragment was never considered an important piece of proof in the first place.

So lets back track. To start, there were several witnesses who were able to testify to the basic facts. Hitler and Eva Braun committed suicide and were cremated outside the bunker, their remains then thrown into a crater where they got jumbled with other corpses.

When the Soviets came along, they began a search of the area, and were able to recover pieces of jawbone and dental bridge. While Hitler's dentist, Dr. Blaschke of the SS, couldn't be found, two of the technicians, Fritz Echtmann and Kaethe Heusermann, eventually were. As luck would have it, only a few months prior, Hitler had had work done by Dr. Blaschke, as had Eva Braun. Echtmann, found first, was asked to sketch out what Hitler's teeth looked like. This was compared to the jaw piece that had been recovered and deemed a match. Several days later, Heusermann also confirmed the match. A dental bridge of Eva's was also identified. These are recreations of the sketches of Hitler's teeth, done by Echtmann and Heusermann, respectively, at the behest of Cornelius Ryan when he interviewed them in 1963.

With that, combined with the various witnesses that, while disagreeing on minor details, corroborated the general narrative, the fact that Hitler did commit suicide in his bunker on April 30th was accepted, and remains so. Whether or not more remains were recovered is an issue that admittedly does remain somewhat shrouded, due mainly to Soviet secretiveness. Questions about whether more remains existed came up immediately of course, and there is the claim that at least some existed, which, according to records found after the Cold War in a Soviet Archive, had supposedly been buried in a pit with those of the Goebbels family, only to then be exhumed in 1970 on the orders of Brezhnev and then cremated in secret. There is no way of knowing if they were in fact Hitler's remain of course, nor am I certain that the story has been corroborated. But as with the skull fragment, they are in the end beside the point as their claim to veracity was never certain, and the jawbone was always, and remains, the chief piece of forensic evidence.

Sources:

Kershaw's "Hitler: Nemesis 1936-1945" covers a good deal of ground here.

Cornelius Ryan's "The Last Battle" is pretty dated material in many respects, but goes into more detail on the dental identification process than most other sources I've seen, so I relied on it here.

What questions is the show trying to answer? What evidence does the show present? Do they provide sources for their evidence that others can see?

I'm an armchair historian but I can count on one hand how many times I turn to a television show for historical accuracy and reliability. It is zero times. They need to write an academic book or paper on the subject that can be peer reviewed.