There's the public persona and the private person. I think you may be disappointed by some of your heroes. There's a well-publicized account by a guy I knew back in NY who helped Miles D after he crashed his Miura and there were bags of white powder all over the floor of the car. J Morrison was pretty gone by the time I saw him, after the indecency bust--overweight, not very engaging with the audience, the band just split in the dark when they were done with their set.
The coolest person I met and knew in the industry was not a performer but he made a lot of careers possible-Chris Blackwell, who was described by one writer as louche. Chris had an ear for the "new" music when the majors were still selling dreck in the late '60s and signed a lot of important acts (from King Crimson and Tull to Marley) in the early days of rock-- he was someone artists were drawn to and he helped transform the sound of contemporary music.
There are a few others who were "behind the scenes" who most of you know of by reputation. What's interesting is Morris Levy, long associated with his disreputable "mob" connections, ran one of the first racially integrated clubs in NYC back in the day when that wasn't "cool."
As somebody once said to me, "when you think you're cool, you aren't." And, an awful lot of musicians came to awful ends--sure, I can enjoy Rory Gallagher or Paul Kossoff for what they gave us musically (like many jazz greats who died tragically), but I think a lot of them lived pretty dark lives.
Sorry to be a buzz-kill.