No, it's not. Typically moderators can view content that needs moderation, i.e. is visible to other users. There is no reason to give them access to all private videos, which are different from unlisted.
Yes it is. You can keep saying "no it's not" until the cows come home, but every single bit of unencrypted content (and possibly well known hashes of encrypted content) is subject to moderation on any large corporate property.
If it was an unlisted video, the moderator would just need to know the reference code (URL) for the video, and could share it with anyone.