I don't know much about NiceHash other than it has a sketchy reputation and in general cloud mining is a scam, but just a heads up, OGNasty has a history of convincing users on this forum to invest their money in massive scams, butterfly Labs and Pirateat420's ponzi most notably.
NiceHash is a website in which owners of mining equipment can offer their equipment for lease via their platform. The work is served via and returned to the nicehash platform, so they can detect if you are actually providing the advertised hashrate.
Obviously NiceHash is legit. Twitchy is still trolling me and spreading lies as a result of a failed extortion attempt years ago. It’s best to assume anything he says is the result of an ulterior motive as it appears the account’s sole purpose is to try and extort gambling operations and established Bitcoiners.