re: Most of my friends are or were stoners.
I grew up in the 70's so pot was everywhere. All my friends smoked it. It was common. A lot of them didn't start drinking for another decade or two. These people are pretty much straight these days. Some were professionals way back then, some are now. I think, as with anything that is pleasurable or addictive; it depends on the person themselves.
Alcoholics are worse than pot heads in my opionion and do a lot more damage to their families and society in general. (I am not talking about other drugs here, such as heroin, cocaine or meth. People who spiral downward into drug ABUSE have major mental health, depression or identity problems.
I think pot should be deciminalized, at the least.