YES...

East Terminal

Ticket terminal East, Gates A, Baggage claim East

NO SMOKING IS ALLOWED IN THE AIRPORT , YOU CAN SMOKE OUTSIDE OF THE AIRPORT...AT YOUR DISCRETION...

That's the administration building for what used to be a toll plaza. In the wake of 9/11, about 5 years after the airport opened, they completely redid the parking strategy to charge you as you exited the lot, rather than a massive toll plaza. They also did away with the hour of free parking for people picking up a passenger. All that remains of the 30 lane toll plaza is that building.

Nope

That's not really the right question. The real question is whether or not you will be able to board the plane, and if not, will you get arrested. Weed is legal in Colorado. Also, TSA agents are concerned about hazards, not drugs. If you are flying domestically out of Denver, the chances of the TSA agents caring about your weed are slim to none. It's just as benign as a pack of cigarettes or a 100ml shooter of booze to them, both of which legally fly. If they do care, they can do one of two things: make you throw it out, or call a cop. If they call a cop, they will not care as long as you are of age, because weed is legal in Colorado. Also, airport dogs are generally not trained to hit on drugs, they hit on explosives. If they do hit on your weed, remember that weed is legal in Colorado, and you are probably not going to miss your flight over it. Flying between legal states should be the least of your worries, since no cops will arrest you when you take off or when you land.

Yes

Yes

B gate is 3300' long. You should be able to make it just fine.