Any place on the body including head

yes u can tag the runner out any where

Ideally, you're tagging the part of the body that is closest to the base. But bad throws, players trying to avoid tags, etc. will sometimes cause you to tag a runner wherever you can. As long as you get the out.

WHY NOT. I USE TO GIVE THEM A GOOD SHOVE WITH THE TAG. THAT WAY THEY REMEMBER YOU.