If Marvel won't even allow the Thing or Nick Fury (the real one ) to smoke cigars on panel, I doubt you'll ever see them use any recreational drugs. Many still consider the use of marijuana as a gateway drug because of the THC. If you live in a red state like I do, it's highly unlikely to see marijuana become legal. Heck, they still don't sell liquor on Sundays here. And as someone else mentioned, mainstream comics are likely to remain kid friendly. Parents would not be keen on the idea.
BTW, I disagree with Ben Grimm being on the list. I can't see him doing it with children around in the Baxter Building.