The problem with NV is that the NCR was the only reasonable choice. The Legion was obviously out, and so was house and wild card, for the sane region. Independent city states do not last long against expansionist nation states, particularly not ones like the Mojave that have nothing going for them. Vegas and the dam are the only notable things the Mojave has, outside that they're screwed. No industry, no farms, uneducated population, nothing else. And Vegas is useless except as a tourist trap, and the dam's value is likewise limited. What's it going to power, exactly?
What is your meaning in this statement?
The power structure in Vegas is "do what the man with the robots tells you to do, or else". There's nothing being done to build Vegas into a society or nation, it's been set up as an autocracy ruled by force alone, and that system won't last. Or worse, it will last, because as you say he's not likely to die anytime soon.
That is exactly true. House's securitrons have one response to legal misconduct, bullets (there's a reason the NCR demanded that they be able to post their own law enforcement on the strip). House also deliberately set out to create Gomorrah, an entire casino that runs on human misery from top to bottom. House has zero regard for the welfare of those under his rule.
And as for his force projection, remind me, what does he do with that? Oh, right, he conquers the entire region by force and punishes anyone who sided with the NCR, even in places like Prim where he has no legitimate claim to authority.
But those are both just side issues to the real problem with house, which is that he's a bad leader with stupid plans. House handpicked the leaders of the new casinos he was building, and exactly one of them stayed loyal, Marjorie. Benny was his protégé and he turned on house, along with most of the Omertas. And even Marjorie had a bunch of her people plotting behind her back, and without player intervention they'll succeed, so really he's 0/3 there. Once that backfires, house switches to you. And, presuming that you're not at this point a renowned hero of the NCR or the legion and thus obviously have divided loyalty (but you totally could be by that point) you are still close friends with a member of the brotherhood of steel, aka the group of people house wants to murder because they (correctly) thinks he's an abomination of prewar science running amok. Association with any of those 3 groups is a massive red flag, and yet house trusts you anyway, something that gets him killed.
As for his plans, house's plan goes something like this:
1. Humiliate and backstab the most powerful country in the wasteland, while also relying on that country as a revenue stream.
2.????
3. Build spaceships using a highly educated workforce you don't have, built out of raw materials you also don't have, launched from a rocket test site that doesn't have the facilities to get something out of the gravity well.
This is a stupid, bad plan. House knows that the kind of stunt he's planning might backfire and make the NCR hate him even more, because he's a prewar citizen and knows that exactly that kind of thing has happened repeatedly in the past. House also knows that while losing the dam will hurt the NCR, losing the revenue from the NCR will destroy him. He also knows that he has no access to the educated workforce he'd need for his spaceship plan, because the Mojave has no education system because he didn't set one up (and when he stumbled onto vault 21, which had an educated population called of maintaining its advanced technology, he destroyed the vault and scattered it's inhabitants to the four winds), meaning he'd have to import those people from the NCR. He also knows the Mojave has no industry and that many of the components and machines he'd need would have to come from, you guessed it, the NCR.
Knowingly all that, it's very clear that house's future plans utterly depend on continued access to and trade with the NCR, which makes his plan to antagonize them incredibly stupid.
