Oh - the families of Burg Eltz have been never active as robber-knights. For this you have to go to other castles. Still a few hundred years to late. Maybe we can arrange something ;-)

We trained to Moselkern, had a taxi waiting there to take us to Burg Eltz(somewhere around $20). You can't drive right up to the castle, so you will have a short walk. When we were finished, we hiked the trail back to the Moselkern train station. The walk to the station took about an hour and a half. At no point did we feel unsafe.