I didn't get an answer to my post, so I went ahead and experimented. First, if you install the Mobile Joomla Ad Remover plugin, you can optionally remove the whole footer (including your own site's copyright). Then, if you want to make a copyright notice for your site, create a custom module in Joomla and insert it in the mj_all_middle position. (I couldn't seem to get anything to show up in the footer). Anyway, even though it's in the middle section, it comes into the page below the regular sections so it was good enough. Hope this helps somebode.
