Okay...
I would hazard a guess that you can find a study showing that a stiff wind can be associated with a higher risk of "risky sexual behaviour" in teens. Drugs do not drive the reproductive urges of teenagers, hormones do. The biological need / desire to mate is something hard wired into every species on this planet. As a young man i used to think that i needed to get a hot rod car in order to have any chance of getting a date. As i have become older i have realized just how foolish i was. But i can tell you for a fact that i worked my butt off to get a nice car
Cannabis use does impair you, as does every legal / illegal drug. What cannabis does not do is take over your mind and force you to smoke wacky weed 24 hours a day, 7 days a week. There is more than adequate scientific evidence showing that people are perfectly capable of being safe, solid members of society even though they partake of cannabis on a recreational basis.
Agreed on the third statement... Isn't that the point? your partaking of a drug on a recreational basis to in order to "take the edge off, enjoy an adult beverage...." etc whatever word you want to describe getting a bit buzzed.
For what its worth, i would say that Clampy is ignoring far, far less scientific studies than you are
In regards to the final bit. Sure designated drivers are a great idea. But you still have not answered my question. If you choose to partake of "weed" were it to become legal would you do so at a time when it's likely that you will need all of your skills, mental and physical, or will you do it in a downtime similar to when you would likely enjoys a scotch on the rocks now?
You don't even need to answer. You would do so when it's safe to do so... same as every other reasonable responsible person on the planet.