My curiosity got going when you asked about Billy Name, so I hunted a little on the net and found this site
http://www.bway.net/~modcult/billyalixp1.html which seems to illustrate that he’s still alive and still very much into photography. Seems to be quite the hotshot in New Yawk.
I found another site, that I won’t list because I’m not sure if it’s even him, but let’s just say it’s a great big picture of a guy that looks like a geriatric Rumpelstiltskin.
It’s probably him, though! 
Yes, you can still stay at the Chelsea Hotel, creaky. I couldn’t afford it, or believe me, that’s exactly where I would have stayed. (We stayed at a place called the Chelsea Lodge, about one or two blocks from it.) From the outside, it looks rather seedy, but a lot of cool places in NY look crappy from the outside. The inside has obviously been redone, and is pretty nice. Not five-star, in my opinion, but I’d think people stay there for the reason I would have: it’s famous!
You’re correct about the part regarding drug usage in the mainstream sixties, too. But I was mainly referring to people such as Edie, Warhol, and their group. The ultra-rich, the jet-set, etc. got into the drug scene long before it became popular. Hell, these people were using cocaine like salt on french fries before mainstream America had discovered the fundamentals of marijuana! I remember thinking when I read the book that it seemed just about everybody at the Factory was so high, that no wonder they all thought Andy’s work was so great. (Which I happen to agree, and I happen to be quite sober!) Think about it, just about every page of the book mentions drug usage. Of course, Diana Vreeland came from upper echelons of society, and would publically frown upon such goings-on, regardless of her personal views.
In actuality, Edie probably couldn’t have handled the work, stress and attention of a mainstream supermodel. She didn’t last long at the underground level, as we have seen.