You might, but it wouldn't be the best idea.
eat and drink less
Alcoholic beverages are high in calories, if you drink those it will be hard for you to stay within the allowed calorie budget required to lose weight. But sure, as long as it fits in your calorie budget you can have pretty much whatever and still lose weight.
It depends on how much self-discipline you have. If you exercise and don't replace the alcohol with food, you can lose as much as you want to.
no alcohol contains a lot of sugar, stay away from it in order to lose weight
You can do whatever you wish. However, that will not help you lose weight. A sensible diet and exercise will be effective.
Usually not. Usually when people go on a diet it's because they want to lose weight. And losing weight means cutting back on the amount of calories you eat and drink. Alcohol contains a lot of calories, so drinking alcohol while you try to lose weight will make it harder, maybe even impossible to lose weight.
Alcohol causes weight gain and therefore, by eliminating it from your diet, you will stop gaining the pounds from the said alcohol. However, if you do not exercise and have a balanced diet, you will not lose weight from eliminating alcohol.
kill you
If you only drink water, and don't eat anything, there is no need to vomit(as you will only vomit out stomach acid), you will already lose weight, and probably be hospitalized sooner or later from problems arising from nutritional deficits.
water and lots of it
You cant. Alcohol is the known as liquid calories. One small mixed drink is like eating a large french fry from McDonalds. And most people do not normally drink just one. If you do want to drink and lose weight you would have to keep the drink very organic like a vodka and water only type of drink.