(SPOILER)Yeah, what Mirage said for the most part. A lot of those questions were answered either directly or hinted at in the show. Especially hosts not being able to harm humans. And Dolores definitely has some things happening with her program. It's been heavily implied that the problems that affected her father have passed to her, and it seems she might have passed it to the one running the brothel. I'm not convinced it's actually a matter of faulty code though. I think the update either included code to secretly awaken them to what's been going on, or there's a flaw that has started to awaken them and she's simply processing it all better than her father was able to.
As for how there are enough people who have the money to go there, I'd imagine it's a pretty massive attraction. The sort of thing that many middle class families and individuals might be willing to spend years saving for. Not to mention there are a lot of people in the world who, while probably not mega rich, have earnings into the millions per year. A quick google search tells me that even in 2009 it was more than 230,000 in the US alone. There's a lot of potential customers is what I'm getting at. And even still, they basically all but said in the last episode that the park is one part of the business but that there's a bigger picture beyond that. Likely the park isn't even the most lucrative facet of this technology.