Couple of answers:
Two levels, each but is about 12" at it's longest dimension, Baby Bullet is 13 7/8" in diameter. Racks are 4" apart which is JUST enough for the butt on the bottom.
I've only cooked one long cook in the Baby Bullet, 7 hours for chuck short ribs. I started a little low on fuel and had to add some at the 4 hour mark. At the end of the seven hours I had about an inch of ash in the bottom (Smokey Joe Gold - no bottom vent). This time I'm using the Minion Method with a full charcoal basket and only about 6 hot coals to get things going. I used Jack Daniel's charcoal for both smokes.