Does Confluence have protection against spam bots?
Yes. To protect against spam-bots, Captcha can be turned on for editing pages and for creating comments (or requesting an account, not relevant for us).
To avoid impact on legitimate users, Captcha has possible (global) exclusions: No-one / Signed-in / Members of a group. Signed-in is the default and is what we are using at this wiki. Signed in users are exempted from Captcha, and so only anonymous users have to go through Captcha. It is then still up to each space's admin to decide whether anonymous users are allowed to edit pages or to comment.
Can I get notified when someone edits a page – or edits any page in a space?
Yes. One can "watch" a page or a whole space, and receive email notifications when someone creates or edits a page:
To watch a space:
Browse -> Advanced -> Start watching this space
To watch a page:
Tools -> Watch
How can I paste in entire documents - pdf, word, ODF?
Confluence can import a word document into the wiki markup. Choose the Doc Import command from the Tools menu.