The Wall/WMG

Tommy from The Who's eponymous rock opera is an alternate version of Pink
In Tommy's version of events, the father survived the war in a POW camp and returned, only to engage his wife's new husband in a fight to the death, which traumatized Tommy and made him enter into a near-catatonic state. When cured of this state, he briefly becomes a quasi-religious figure, protected by guards that assault Sally Simpson when she tries to get up on stage with him. In Pink's version of the events, the father died, and Pink's many negative experiences led him to build a "wall" around himself to keep others out. As he descends deeper into psychosis, he imagines himself as a fascistic dictator. This sequence grew out of Roger Waters' concern at having once spit at a disruptive fan at a concert, similar to the incident with Sally Simpson depicted in The Who's rock opera.
 * I, Prime Evil, am having a vision of Pink befriending Tommy and joining forces with Ziggy Stardust, Rael (The Lamb Lies Down on Broadway), and, at a stretch, the Patient from The Black Parade and forming the next League of Extraordinary Gentlemen.

Pink got a Happy Ending.
After the Wall was torn down, he quit show business, became a lawyer, reconciled with his wife, had two kids, wrote an autobiography that became a bestseller, retired at 65, moved to Florida, and passed away peacefully in his sleep at age 93, whereupon his soul went to heaven.
 * Really takes away from the High Octane Nightmare Fuel, doesn't it?

Pink does not run into the bathroom and hide during Stop. He actually has a seizure onstage.
During the song In The Flesh, Pink yells abuse at his audience. He then falls into a seizure as a result of the drugs the doctor gave him in Comfortably Numb. What appears to be days roll by (Run Like Hell, Waiting For The Worms), when really, only a few minutes pass. Pink hears the door to the concert hall open vaguely, which is paramedics coming to help him. He then goes through The Trial, at which point the Wall collapses and Pink is set free. He returns to a psychiatrist later on, however, lamenting how he didn't kill himself (The eponymous track on The Final Cut).

Pink's real name is Floyd Pinkerton
Considering his father's name was "J.A. Pinkerton," it seems reasonable that "Pink" became a childhood nickname that he later adopted in adulthood. Hence, his full name is Pink Floyd.
 * It's *something* Pinkerton, but not necessarily "Floyd Pinkerton." The "Floyd" part comes from his wife...he'd have to take her name in marriage, but it makes sense, given how he views himself.

Pink is being tongue-in-cheek during the fascist rally sequence
Believe it or not, this is possible, given the theme of the album (poor communication results in misunderstandings). Inspired by colleague Ziggy Stardust (that universe's version of David Bowie), Pink decides to try on a new persona and play a joke on the audience. Unfortunately, the audience isn't in on the joke, and so they take him seriously. And he takes them seriously in response to their taking him seriously. And on and on it goes until the joke is no longer funny.
 * I doubt that. Considering how hopped up on drugs he was, he wouldn't be coherent enough to pull something like that.
 * You'd think so but David Bowie actually managed to pull a similar stunt while having a cocaine inspired mental breakdown.
 * Who says Pink was "hopped up on drugs?" To many interpreters, the Doctor gave Pink something that stopped the high, or at the very least knocked him out of his self-contemplation. That made him angry enough to sabotage the rock'n'roll show and make his manager do an unfathomable amount of damage control. Though all this assumes he was actually performing during the fascist rally sequence.

Mrs. Floyd wasn't actually having an affair
Remember, he's calling her from a long way away. He's also so far up his own ass that he is unable to learn the truth: the man who answered the phone could have merely been a friend of a friend, or even a distant relative (a cousin, or brother-in-law). All we learn from the unhelpful "connector" is "There's a man answering." All he says is, "Hello?" It's Pink who puts 2 and 2 together, and gets either 4 or 5, depending on your interpretation.

"Welcome to the Machine" from Wish You Were Here tells about how Pink got a record contract.
Some of the lyrics seem to pertain to Pink's character. ("You bought a guitar to punish your ma" and "You didn't like school" are definitely true to it.) Plus, the sleazy executive might have been another "bad influence" that just got pushed aside for the final cut. Sure, Waters wrote "Welcome to the Machine" before The Wall, but the two seem to be connected.

The Wall is about the cycle of violence.
the theme of both the movie and the album are about how violence leads to more violence in a vicious cycle, starting with relatively minor examples leading up to a huge one, some of the cycles are, the teacher being abused by his wife and thus taking it out on the kids, the mother taking out her fear and grief over her dead husband on her son, Pink being abusive towards his wife and his wife cheating on him as revenge which just hurts Pink even more and finally Pink's white supremacy stemming from his resentment of Jews over his father being killed in WW 2.
 * Yes and no. The odd one out is the third--Pink was never truly abusive toward his wife, merely non-communicative (it's implied that his mother's sheltering led him to never really "discover" the opposite sex in a truly personal way). The fourth also doesn't quite work because Pink's angst comes more from having never known his father at all...the war is sort-of beside the point (i.e. the father's absence is a side-effect of the war, but a big one...it could have been anything from death to divorce. WW 2's effect on the British psyche is a whole 'nother can of worms entirely.)

Hitler built a Wall too.

 * As stated on the main page, Pink becomes what his father died fighting against. Hitler was a failed artist who became a fascist leader after the events of World War Two. He rose to power playing on the resentment and hatred that occured in Germany in the aftermath of World War One. Perhaps Hitler's descent into villainy (or Mussolini's, or Hirohito's, or for that matter, anyone in that position of power and influence, whether in art, politics, culture, and so on) came by building a Wall similar to Pink's? Perhaps those who followed Hitler, etc. and believed in his policies and prejudices had Walls, too. Could the cycle continue with other people, from other walks of life, building Walls because of miscommunication and alienation?

Is There Anybody Out There?
""Does anybody else in here feel the way I do?""


 * "Is there anybody out there?" Yes and no. There are others out there, but perhaps they too have Walls. Pink, being in a position of power/influence/mass communication as a rock star is able to lead the Hammers to totalitarianism, playing on their fears and alienation/miscommunication. Who are the Hammers? Those without power who have their own Walls as Pink did--for whom the Worms ate into their brains too, and for whom Pink is calling out to. They become the Hammers as Pink leads his rally. If he can't communicate with them in a loving way, he will through hate-mongering. "United we stand, divided we fall..."
 * "...some hand in hand, others gather together in bands, the bleeding hearts and artists make their stand."

Other than that, the rest of it's pretty much Word of God. Roger Waters himself is a believer in cycles of behavior, not necessarily of violence and aggression but also of paranoia and of miscommunication and outright lack of communication.

In-universe, the album The Wall was made by Pink and his band as part of his recovery process.

 * In 1980, sometime after Pink's on-stage breakdown and his inner "trial", he and his band made an album documenting the events that led up to the fiasco and explaining his mindset at the time. The storylike structure is assisted by recurring symbols, musical motifs, and even multi-part songs ("Another Brick in the Wall" and the "In the Flesh" series). The album even has older songs he made to help tell the story, such as a shortened operatic version of his old charity single "Bring the Boys Back Home." He made the album as part of his recovery following the chaos of his life. This explains how the musical-theater style fits in-universe and also why the crowd repeatedly shouts "Pink Floyd!" (Pink's band's name) in "Run Like Hell", as well as the numerous Shout Outs and allusions to earlier Floyd works.