Marijuana is not a gateway drug. This has been studied extensively.http://canadaonline.about.com/od/marijuana/a/senatemjreport.htm. Most people start out with beer, actually - it's a Canadian tradition. And there's no way I will believe your friend died from smoking marijuana.Many heavy drug user started this way:-"Oh it's just a weed- don't worry".
I had a friend who already dead and she was 27 then. She started weed when she was 20. Yes a few people can control this "weed" habit, but 80% of them going to the next level.
And to further counter your anecdote, I've smoked pot off and on for over 30 years. So far this summer I've been in 1 x 5 km charity run, 2 x 10 km charity runs, the Toronto 10-Miler, a sprint triathlon, an Oly distance triathlon, and will try to finish a marathon in a few weeks.
After which I'm hoping to see one of my favourite SPs - and maybe smoke a joint with her.
I don't see how Rhianna's attractiveness factors into this at all. And being a performer, whether she hangs out with strippers or has a squeaky clean image like Tiffany or strange aesthetics like Bjork she's going to attract a lot of attention, both wanted and the creepy unwanted, "I'm your biggest fan" type.
And anyone who's actually listened to her lyrics can not be surprised about her checking out a strip club. Her songs aren't about going on a picnic with a nice boy she hopes will ask her to the prom.