How can I exercise my religious civil rights when my landlord is violating them,?

There is nothing native american about a pentagram, at all, so don't use this argument, you'll lose. However, it is your constitutional right to religous freedom, so I would argue this one. It is your home, and it is an innocent symbol. Just don't try to pass it off as Native...because its not...and any real native would be the first to raise the flag on this one.