My LFS will not take kenya tree frags (I can't think of any other coral they wouldn't take!).
It is totally safe to touch it. It may leave your fingers a bit stinky, but it won't hurt you or the coral. It will survive floating around by itself, as long as it doesn't get sucked into a pump or powerhead. Eventually, it will attach itself to the substrate or rocks.
If you want to keep it, you can attach it to the rocks yourself just by wedging it in a crack or hole.