I don’t think it’s that big of a conspiracy. I think you have a man who was a degenerate and loner who sat drunk all day gambling his life away and money away.
Gambling big allowed him to enjoy the "high-roller" perks but when you show up to Vegas every Friday with a million bucks and leave every Monday with $995,000, that's called "losing" and eventually you're going to run out of money. Paddock was doing this every night.
When Vegas changed the algorithms of their slot machines to pay out a little less, Paddock viewed this as cheating and with his money running dry, he wanted to teach the casinos a lesson.
I've never bought the crazy conspiracies. The simplest explanation is probably the best; Paddock thought he found the secret to living the good life in Vegas on their dime in perpetuity and when he say things weren't going to work out this way, he became angrier, drunker, and blamed the casinos.