Agreed. Unless it's something crazy awesome like hotels.vegas, you're most likely looking at a buy-and-hold for a few years if you're wanting to make big bucks on it. And that's a big if.
Yep, it's what you do with them that gives them value. Some can be used beyond the obvious such as roto.vegas which is the nickname of Rotorua, a city in NZ but nobody is going to give a damn if someone cybersquats the name. They'll only get excited if you build a really cool site there.
I would say no. If you need further proof that all those new tlds are nothing but worthless crap, please consider that the more sought-after domains are "reserved" by the company running the tld and they charge outrageous prices for them. loans.xyz costs $65,000 a year to register. What a joke. Nobody in their right mind would pay that for a worthless .xyz tld. But wait! There's more! The company that operates the .xyz tld (gen.xyz) will allow you to register it for the low low price of $55,000 a year! Wow! On other registrars it costs $65,000 a year, but on the website for the sponsor of the tld you can save $10,000 a year! Wow! What a deal! icann.org/resources/agreement/xyz-2013-12-05-en
Buying such thing is kinda risky, unless like what Goob said if you associated it with a good domain, or if the site is very interesting then that would be enough. How much does it cost you anyway??
The crazy things about domains are they're worth what a single person thinks they're worth! A million people could say RandomDomain.com is only worth $10, but it only takes one person to think it's worth more and pay above that. The problem with these vanity urls like .vegas is that your potential pool of people who might buy it will shrink. Kings.com would be a no-brainer, but Kings.vegas is only valuable to somebody in the Vegas area/community. I could theoretically see kings.vegas or visa.vegas being worth $XXXX, but it'll take more effort to sell.
I agree that it only takes one but as a smart businessman--at least I think I am--I try to find domains with mass appeal. That way, I don't have to spend the time and effort to market to millions of people, I can hit hundreds and make the sale.