For the first, and I'm not entirely sure on this, I don't think there is a function directly for getting the master account. If I'm not mistaken, however, you could get the list of all administrators and shift off the first one. I believe the first account is always the master account, but yet again, I'm not sure. (see http://www.zenphoto.org/documentation/functions/Zenphoto_Authority.html#methodgetAdministrators)
For the second, there is an accessor for the `_Image` class that will retrieve the copyright field. You should be able to use `$_zp_current_image->getCopyright()`. (see http://www.zenphoto.org/documentation/classes/_Image.html#methodgetCopyright)