It's always better to take permission from the respective authors.
You could post a small book on this. I believe the short answer is yes. I believe NING's design studio would fall into similar territory with Wordpress - where the argument is that you can't "create" anything if you're using their platform.
If you're using the NING design studio, you would not be able to legally protect your site just because you chose yellow borders with a pink background and a particular font.
one thing you can do to (SEMI) protect your layout/template is use images you created for headers,mod backgrounds, etc as you would own the copy on them.
It depends. As always.
If the design is trademarked, it is considered as a form of property. In this case, copying means trademark infringement, which can become costly quite quickly.
What is wrong with politely asking the owner of the community if it is OK to use parts of the design anyway?
lol read this for the answer.... NAUGHTY MICROSOFT
Thanks guys, my own perception is that copying special code is illegal (except for the stuff you can find in Creators forum), but using design within the framework of ning should be without problems.