If I smoke weed it will not affect the ability for my potential son to handle it any better in anyway shape of form. It's not a trait with an ability to get passed on. It's not recessive OR dominant, like hair line, or height, alcoholism, etc. Tolerance is not a trait that gets passed on. If you smoke your tolerance goes up and sperm count goes down. Stop smoking and your sperm count goes up. It's only directly related to useage, not genetics. Biology does not work that easy. But you are on the right road with selective breeding. But you cannot affect the dominant or recessive traits by smoking more or less.
Tolerance is not even a trait found in genetics, it more like a variable affected directly by using the given stimuli.