Also, if the Courier doesn't intervene (either dead from Benny/something else or just decided "screw this I'm outta here") then would Ulysses be motivated to launch the nukes at anyone? He launches because of the Courier, he blames them for taking away the Divide but if the Courier's dead or not interested in helping the Legion/NCR and then following him to the Divide, how would Ulysses know of the Courier's allegiance?
If the Courier doesn't intervene it doesn't change the fact that the Divide happened. It happened because the Courier took a job to take a package into the Divide which set off some of the nukes and exploded the Divide. If this Courier doesn't do that it is still a job he accepted so someone else would have made that job. It would still have happened just not caused by this Courier.
Ulysses launches the Nukes not as a revenge but because he saw that one man can change history, so he decides to change history himself. He attracted the Courier to the Divide so the Courier dies there (he still respects Caesar order of not killing any couriers, so he tries to have the Courier killed but not in a direct way), if the Courier died before reaching Ulysses or something, Ulysses will still launch the Nukes into NCR because he considers that the act of his conviction (he even says it is not about revenge, but conviction) because he wants to be able to erase the NCR history just like the Divide history was erased.
Yes, in 3 out of 4 endings the NCR take Hoover dam. Statistically this makes it the most likely outcome.
This is because the Legion got most of it's content not implemented because of the short time Obsidian had to make the game. The Legion would have gotten at least the same amount of content as the NCR or even more since we would be able to visit a real Legion settlements, as J.E. Sawyer said:
The additional Legion locations would have had more traveling non-Legion residents of Legion territories. The Fort and Cottonwood Cove made sense as heavy military outposts where the vast majority of the population consisted of soldiers and slaves. The other locations would have had more "civilians". It's not accurate to think of them as citizens of the Legion (the Legion is purely military), but as non-tribal people who live in areas under Legion control.
While Caesar intentionally enslaves NCR and Mojave residents in the war zone, most of the enslavement that happens in the east happens to tribals. As Raul indicates, there are non-tribal communities that came under Legion control a long time ago. The additional locations would have shown what life is like for those people.
Yes but how long has he been there? The Courier was him getting lucky, so who knows how long he'd stay there trying to get in if they never show. It's easy to say he'd get someone else, but I don't think it would be likely nor anytime soon.
Unfortunately the game never tells us how long he has been there or even an approximation.
Elijah have managed to follow up with his plans all this time, he didn't account for the Courier so it is only logical that he has other plans not involving the Courier. Maybe because of the Courier his plans will advance a couple of months earlier, who knows. But he is extremely intelligent and resourceful, he managed to reach the depths of the casino with a previous team of captives (without needing the Courier) and he still has Christine, God/Dog and Dean around, he only needs the vault open to succeed right now and that is what the Courier does for him. Elijah already completed 95-99% of his plan without the Courier, it will take a while but I have no doubt he will succeed sooner or later.
and House no longer bleeding them dry (note that w/out the Courier his plan goes absolutely nowhere)
I would say that without the Courier House would achieve his objectives. Without the Courier, Ulysses would be the one taking the Chip to House and he is way tougher, experienced, trained and careful than the Courier (would probably avoid the main roads), I don't think he would be ambushed as easily and even so he would be able to take care of the ones who ambush him since he is the toughest character in the entire game and DLCs, is 15% faster in movement and action times than other humans, is the only human in the game and DLCs with more than 1000 HP and has all SPECIAL values maxed.
Perhaps. I can see why it was cut, even with the DLC's tone in mind it's way over the top.
But the DLC is still cannon, so we can't just hand-wave it to suit our needs.
There is also the over the top not cut ending of Father Elijah releasing the cloud and killing everything.
The NCR will not last long, it is being attacked by all sides without even knowing. Elijah wants to destroy the NCR, the Legion wants to conquer it, the Think Tank would enslave it with mind control, without the Courier the White Legs will join Caesar's Legion, the remaining Khans will join too, the monorail will be destroyed, NCR camps will not get any supplies they need (the Courier is the one that helps several camps with the supplies they need), and so on.
PS: Remember that Chris Avellone thinks that both the Legion and NCR will destroy themselves and should be "cleansed by fire". I have no doubt that he helped make FNV take that direction, everything we see without the Courier's intervention shows that both would end up destroyed (Caesar has a tumor he is not aware of and the NCR has all of these powerful forces that can destroy or enslave it in the end without the Courier stopping them).
Lastly, with regards to the DLCs, I believe Ulysses is correct, a new framework of civilization is the only solution for the Mojave and the Legion and NCR are self-destructive institutions (the Legion is more a slow burn than NCR is) and both should be cleansed with fire. Also, in Dead Money, Elijah's not only frustrated with human nature but he also makes several pointed comments about hand-holding in RPGs, which may be voicing my views on the matter, since I can get a little grumpy about it.