The shulchan aruch (well at least the gemorah and im sure its in the siman about yichud in EH~22)says you cant have yichud with her anyway. As for touching, I would tend to assume that its not appropriate, though I am subject to the same biases that you are. However do you have a source that anyone says its a problem? Its definitely NOT lo sikrevu. The structure of most of these prohibitions is Los Sikrevu.
RH: Suppose a 16 year old did go. Do you dispute that she is still forbidden to be touched by anyone?