He's got amazing people skills tho and somehow manages to keep his act together as a law student and competitive athlete. Should this be a concern?
Don't date him, and keep your distance. First, he may be high-functioning today - he might not be tomorrow. A future dead end for you.
Second, he's a police arrest waiting to happen. You don't want to be in the vicinity when that goes down, because of the risk of implication.
Third, as these guys waste their money on an expensive habit, they begin to lie, cheat & steal to support their addiction. Even from friends & family, because their craving makes them lose all morality and self-respect. They become hopelessly desperate. You may not see it now, but if he doesn't stop early it's coming.
I once stayed overnight with a guy in Minneapolis out of convenience. My good friend, with whom I normally stayed when I was in the Twin Cities, had some conflicts that prevented him accommodating me my first night in town, and until late afternoon the next day. But my own schedule commitments forced me to arrive a day before that.
I knew this other guy from AOL gay chat rooms only, had never met. He offered to put me up, so I took a chance. In return I provided him supper. He seemed like an OK guy.
All went well until the next morning. He woke up early, and when I awoke I heard all this door knocking and talking with different voices. I got out of bed and saw him in the front doorway of this older inner-city house he rented, right on the sidewalk and a busy street. With a steady stream of morning "customers" coming up, conducting business right in plain view, exchanging money, not even going inside out of sight.
When he came back inside he freely admitted he was dealing drugs, these were his regular customers. How he supported himself, and kept his own habit going. He showed me a large clear plastic bag filled with pills of every color, and he had weed, too. He offered me some, which I declined.
He was just begging for the police to see him, or neighbors to report him. OK, I didn't want to be there during a police raid, or covert surveillance. I was outta there NOW! I made my cell phone ring, and faked getting an imaginary call from my friend. I told the other guy that my friend's plans had changed, and he wanted me to join him right away for late breakfast.
I packed, gave my thanks, and jumped into my car. Of course my friend wasn't gonna be home until 4 PM as previously planned, so I just killed time in downtown Minneapolis until then.