Thanks for your feedback. I posted this because I've seen many people stop their analysis when they find a site is on Cloudflare.

Were you able to solve the challenge at the end?

I thought the non-random nameserver assignment was interesting. Seems like a flaw, actually.

No, you can't. The article even says that Cloudflare provides WHOIS redaction.

But you would know that if you actually read the article.