When all else fails, there's always the courier
Every faction in Fallout New Vegas has their flaws. The NCR try to bring civilization Mojave wasteland but drive away anyone unwilling to fall underneath their laws and their taxes. The Brotherhood of Steel would rather follow tradition to the death, hiding in their hole trying to outlive the denizens of the wastes. And lets not forget the Legion. No one with a functioning brain would ever support these guys.
But lets say you successfully ousted all major factions gunning for control of the Mojave and you took control. With the Legion, the NCR, and Mr House out of the way, how would you run things? In this scenario the major factions are out of the way leaving behind only the minor factions (Brotherhood, Apocalypse, Khans etc). What kind of leader would you be? Who would you take on as allies? Who would you consider your enemies?
I would fully back the Followers. They could move into the former NCR embassy. Assuming I had control of the Securitrons via Yes Man, they would go out and support the Followers in bringing education, technology and medicine to the local wastes. I'm not sure how "complete" that control is, since the game describes anarchy taking hold without House in the picture, but I assume that would be the result of a bid for power from the Strip families. I'd join Freeside to Vegas proper, shut down the Atomic Wrangler, Ultra Luxe and Gomorrah.
I'm not big into politics, so I don't know what kind of government would emerge, but assuming the Followers took to their role, I trust them enough to choose one. I'd reach out to the Boomers and the Brotherhood(Helios One might have to be sabotaged first), but probably remain distant from the Khans.
I think you're right. I thought about joining in on a previous debate but didn't because of the Rules about political controversy. With Fallout the lines are blurred. TES is fantasy, Fallout is based more or less on our reality. You could argue that even lasting peace is best achieved by conquest, ie China.
The White Glove Society and Omertas are not by any stretch the most important people in NV. One is a group of relapsing cannibals, and the other are thugs and sex traffickers who already had planned to overthrow the Strip. Shutting down their operations is the only logical thing to do, cutting off their funding and forcing them to work in the open, or leave. For people who still want to get drunk or gamble, Vault 21 and The Tops are still open, and will benefit from having some of the other casinos' business directed towards them.
Why would there be an underground? The Followers have skilled engineers, and with their help, new housing could be built, and old buildings renovated so people could use them again. Opening the strip to Freeside would simply create more opportunities for people.
The Boomers and Brotherhood both have enormous needs to meet. The Boomers will eventually need a source for gunpowder, which I'm betting I'll inherit from House. And the Brotherhood has no source at all for food, which we can provide with the sharecropper farms. That said, the Boomers are hardly necessary as military when I can use the upgraded Securitrons without sacrificing humans, but their help would be welcome. The Brotherhood, on the other hand, isn't going to be anyone's military, but opening trade relations and making so they can leave their bunker without being harassed will mean they can carry on their operations, which will discourage raiders.
I didn't say anything about pacifism, either.
Oooh this is an awesome question. (These aren't necessarily chronological)
Step 1: Find engineers who can attach hands to Securitrons, like with actual thumbs. This way, I won't have to hire humans who require money to work.
Step 2: My courier is already friendly with the Kings and the Followers. Using them, I will reclaim Freeside and lower the price of entry to New Vegas to 400 caps. Much more reasonable, and more business for the casinos.
Step 3: Speaking of casinos, give control of the casinos to the Followers. They will still be casinos, but the prostitution will stop at the Gomorrah, and they will all offer help for chem and gambling addiction.
Step 4: Send securitrons to take over McCarran, The Fort, all Ranger Stations, Helios One, Cottonwood Cove, and the Vaults. There only needs to be about 5-6 Securitrons per Station.
Step 5: All caravan expeditions will have a Securitron guard to accompany them. This will boost trade.
Step 6: Clear out I-15 so as to open another trade route. Also, exterminate the Powder Gangers, and reclaim the NCRCF as a prison. Only violent crimes will be punished by prison. Nonviolent crimes will be punished by hard labor.
Step 7: Using the crime labor, I will make the trade routes safer with outposts, manned by human militias. If the Boomers are up for it, I will borrow some of their artillery for these outposts. Militia members pay no taxes for their service. (their family members still do though)
Step 8: Yes, people, there are taxes. However, they will be low, as I will employ few humans. Mainly maintenance and stuff.
Step 9: Give the Khans a choice: They can either give their chem making equipment to the Followers, or they can hit the road. They will receive temporary tax benefits for giving up their stuff.
Step 10: There will be a conscription in times of war. Sorry people. Yah join the place, yah fight for the place.
Step 11: I will attempt to make a truce with the NCR. If successful, trade will open.
Step 12: How to fight the Legion: I will put mini-nukes on the backs of Securitrons, and have them visit Legion camps until they are too weak to fight. Problem solved for a little while.
Step 13: Clean up Westside and the ruins from the Fiends, but allow Westside to remain independant.
With all this in place, the Mojave is set to become very prosperous in the next few years.
It's a good thing. For example, the NCR is spread too thin, so their effectiveness is limited. My approach will be different: "Make supreme, and then spread." Have peak efficiency in industry, agriculture, and economy, and then expand.
Stuff so done you can stick a fork in it.