"Basically, we do not want anyone to copy our WordPress theme or plugins"
In that case, I would very strongly recommend not using WordPress at all. It is GPL (http://wordpress.org/about/gpl/). Any plugin or theme on WordPress is going to be GPL too. And folks who try to keep their code closed source in this community are generally not going to be very well received (eg http://www.ivycat.com/2013/07/a-newbies-guide-to-the-gpl-and-wordpress-licensing/ and http://www.designcrumbs.com/automatically-blackballed).
If you want to close your source code, that's your business. But even so much as trying to do that in WordPress... I mean you can, but it's not gonna go over very well in the community. If closed source matters to you, WordPress is really not the right platform to be on.