Is the water diet healthy?

No. In and of itself, the water diet does nothing to increase health. Set aside the questionable weight loss. The water diet explicitly says you can still eat what you want as long as you ingest 64oz of cold water. So if you were having fast food all day before the water diet, you'd be eating just as unhealthily while on the diet.
Water diet? Not sure what the " water diet" is or consists of - please elaborate..
No. Smoking is detrimental to all the cells of your body. It diminishes the oxygen in the cells and carries toxins to the cells. It causes premature aging and an array of problems for the body. Bad news.