if you eat good meats..like low in sat fat and high in protein..fish, chicken, lean beef are all good and yes it can help your health a lot. but only if its a balanced diet...and cutting out sugar too. but you need good carbs and all the food groups to be healthy.
Meat really only adds fats and cholesterols your body does not need. Certain white meats are okay in moderation, but be sure it is hormone free. In all honestly, our bodies are not designed to digest meat in general very well. Red meats are the worst, so I would stay away from those in general.
It depends on what your body is lacking. if it is lacking the nutrients found in meats then yes. You could also take a vitamin or eat other foods with these nutrients, if you are a vegetarian by choice.