CC-BY-SA needs to be wrapped in div, but not CC-BY?

I understand that* CC-BY-SA *content should be avoided like the plague. But
when unavoidable, content snippets should be wrapped in <div
class='license-cc-by-sa'> as outlined in the External Attribution
<http://docs.webplatform.org/wiki/WPD:External_Attribution> instructions.

However, I wanted to clarify usage of *CC-BY* material so I'm 100% clear on
using external content:

1) No need to wrap text in a div, *even if I make modifications to the
original content*?

2) Only administrators should be able to remove external attributions once
they are set? (I tested on the practice page and was able to uncheck
checkboxes and save -- I'm not an administrator though.)

Thanks,
Pearl