I feel like you either didn't pay attention to the lore or are willfully ignorant. The NCR's occupation of the Mojave is portrayed as self-destructive, certainly, and it has a lot of problems, but as a nation state it is stated to be incredibly powerful. It has working railroads, luxury good industries, working power grids, agricultural planning, satellite communications, organ cloning, cybernetic implants, working vertibirds and well maintained infrastructure. The NCR might seem like a piece of shit in New Vegas, especially compared to House, but the game deliberately takes place on the frontier of NCR territory because otherwise the game wouldn't be post-apocalyptic. Life is pretty damn normal within the borders of the NCR.
Also, the pre-war US was a pretty damn clear fascist/authoritarian government. It outright invaded Canada and openly annexed it (while executing freedom fighters), forced every piece of media to write propaganda, spied on citizens and made them disappear if they were considered seditious, abducted Chinese-Americans and placed them in internment camps, and had a fucking gestapo/commissariat analogue in the Political Office. West Tek was even straight up nationalized in 2076. The parallels could not be any more clear.
Er, no, it isn't. The NCR is practically the weakest of the nation states. Their only power is numbers, a power that the Legion matches them rather well. Except even the NCR leaders like Colonel Moore admit that the average Legion mook is far better at fighting than the average NCR mook, which Chief Hanlon states that they sometimes even lack proper armor or service rifles. Also, most of those luxuries you state are mostly serving the upper crust of society while the rest of the peons are stuck with an army that can't even protect the populace from raiders and monsters while the rich get power-armored troops protecting their brahmin barns. At most, we saw ONE vertibird, and vertibirds aren't even that impressive when focused fire from small arms can destroy them. I can't count the number of vertibirds I blew up in Fallout 3, and Fallout 4 similarly allows you to destroy vertibird squads with enough turrets mounted on your bases. Life in the NCR is practically shit for the lower classes. Caesar's Legion is proof of that; commoners like Edward Sallow and his parents can't even be protected by the NCR from jet-addicted raiders, and that of course, led to Caesar's Legion forming from the mind of a former NCR citizen angry that his country can't even protect its people. The rich and powerful live comfortable lives, but the common man could easily get killed by a deathclaw or have his wife and daughter get taken as sex slaves by random-ass gangs, and the NCR government barely cares so long as the rich people are happy.
No it wasn't. The pre-war US wasn't even close to fascism. Instead, America in the pre-war situation was a democracy with corrupt politicians planning to backstab the people who voted them in. They invaded Canada, but that doesn't mean they're fascist. Older US invaded Mexico and stole their land, and they slaughtered entire Indian tribes while moving west. Does that make the 1800s America fascist? The America of the Civil War and the World Wars also created propaganda, spied on its people for potential traitors, and as per Abe Lincoln's orders, SUSPENDED HABEAS CORPUS. FDR even threw all Japanese Americans in jail. And that was back then when the US was fighting fascists (WW2) and slave owners(Civil War). If that's your definition of fascism, then America during the Mexican War, Civil War, expansion era, and WW2 would be classified as fascist.
Again, you don't even understand what fascism is. Fascism as it was defined by its practitioners is national socialism, ie. taking socialism's authoritarian yet welfare-heavy approach and combining it with nationalism and openly mocking the idea of democracy. America pre-war still openly praised democracy even as its politicians secretly planned to stab their electorate in the back. Fascism openly decries democracy as useless and corrupt, and would openly rule in public without hiding behind corporations and shadow governments. In a fascist system, THERE IS NO SHADOW GOVERNMENT. The Enclave wouldn't exist, because you'd have an autocracy ruling out in the open instead of manipulating democratic governments under the shadows. Companies like Vault-Tec would be totally absorbed into the US government, unable to do things like build secret vaults that the government didn't know like they did in Fallout: Brotherhood of Steel. RobCo would also be absorbed, meaning that Robert Edwin House would become a salaried government employee who can't build jack shit without Uncle Sam knowing, so say goodbye to that defense grid unless the entire country gets it.
But most especially, a fascist government would also have welfare up the ass and practice socialism. The only difference is that they won't throw nationalism or religion into the scrap pile. They'd keep those elements, but everything else from how the government runs to how the corporations become parts of the state, all of it will copy socialist ideas on how things will run. Not only that, but they'd share Red China's disdain for free-market capitalism and democracy, since a fascist detests both as tools of corrupt oligarchs, whom fascists persecute. Especially when Benito Mussolini took over Italy, he started persecuting the Mafia oligarchs who used to run the Sicilian half of the country, hence why the mob was in league with Uncle Sam to take down Fascist Italy. This of course means that a Fascist America would have no problems selling Alaskan oil to China, since while they will detest China's atheism, they will share its socialist policies, and its disdain for capitalist oligarchs and western-style democracy, which means they'll have more in common with Red China than with western democracies..
Once again, I refer you to this picture:
That is the face of a fascist, pal. Not someone who would cry out for democracy and expand capitalism, but one who would utterly obliterate both of them for the glory of the community and the state.