Weed needs to be legalised across the board everywhere. Revenue would kickstart these crappy economies - California is getting closer to making it happen each time they vote on it.
People will not stop using. Regulation would lead to safer preparation and stamp out the crime it's associated with.
Once legalised, I do not see pot as a leapfrog drug whereby users will automatically move to harder, more damaging drugs. For it to be deemed on a par with alcohol, it's more likely that it will prevent users moving on to the nasty stuff.
It's a no-brainer dude.