Am I the only atheist that doesn’t smoke pot?
I smoke pot - but I did so long before I became a non-theist - in no way did it impact my decision to cast aside religion and I'm not implying that you are suggesting that. Having written that, I know a ton of non-theists that don't smoke or drink. Their worse vice is perhaps exercising to excess - a couple are going to have knee or hip surgeries - aside from that - most of the non-theists I know are pretty tame or lame depending on your perspective .
I don't smoke it, but I eat it sometimes. It helps my arthritic hip and shoulder. My son in law also makes a salve with it that helps to.