Devout Christians and Catholics, am I being offensive?

First most of us find it offensive that you appear to assume that being Christian and being Catholic are two different things. Secondly, you should not wear religious jewelry, only as jewelry. This is sacrilegious, even if you do not mean for it to be. This especially true of the rosary and crucifix. I would never dream of wearing a star of David, since I am not Jewish. I think parents will be offended especially when they find out that you are not a Christian and teaching or whatever it is that you do with their children. As others here have said, the parents will think that you are trying to deceive them and their children. You will never win that one.