Can I protect a sub-domain without the main domain being affected?

Tony

Not sure about a subdomain, I think so. It would be similar to what I have done in folder view below. Each of the pages in the expanded folder has it's own unique validation. Although I recall seeing something about not being able to protect a folder and it's contents. I think it was being addressed in an update. Someone should be along with a definitive answer.

Yes it is possible, however depending on how your Website folder structure is setup, the reverse may not be possible.