As long as they get protein from nuts and other things besides meat that contain it then no, but you do need protein.
Yes, there are certain nutrients in meat that you need. If you're going to go full out vegan I would suggest you do research and make sure your taking the proper supplements and vitamins to cover what you're not getting by not eating meat. If you do lacto-ove vegitarian, then it isn't such a big deal because eggs and dairy have alot of the same nutrients as meat
Just make sure you're getting protein from other sources. (soy, nuts, beans... eggs and fish are good options, too, if just abstaining from red meats)
Any one can have health problems if they don't eat a balanced diet.
There are countries where many/most people do not eat meat.
Anaemia is one problem
YES......THE ANSWER IS YES DON'T LISTEN TO THOSE WHO SAYNO!!