If you read it, you'll see that it's basically an explanation of what information they do and do not have, how their various properties work and what information they store, and how much it will cost an agency to have certain information requests addressed. It doesn't represent some sort of sinister pipeline of information directly from their users' keyboards to the "evil government." If anything it's useful to everyone because it shows exactly what they do and don't save, and it might act as a deterrent for the casual or clueless investigator who watches too much CSI and thinks sending a request off will instantly pinpoint the bad guy by backtracking his DNS through the GPS IP address of his netbook's MAC module or whatever.

That sort of disclosure is on almost every statement that is issued by companies that are regulated by the SEC or some other regulatory body. Go look at any company's annual report, quarterly SEC filings, etc. Even press releases might have that sort of language on it. You basically have to try to spell out everything that could possibly go wrong so that stupid investors who don't understand that every business carries potential risks don't sue you later.

...but I personally would not think it was acceptable for them to edit a resume without collaborating with the candidate. If they want to suggest changes and work with them, that's one thing, but changes without the candidate's knowledge are a totally different matter.

Also, from the interviewer's point, they probably don't have the time or interest to weed through "why" it's wrong. And yeah, they may check in the future, and if stuff does not line up you might be held accountable for it. So even from an interviewer's point of view, it creates a potential problem. I would find another recruiting firm if you think it is beneficial to use one (I don't, necessarily, but it depends on your career and the types of companies you are looking for).

P.S. To question 3 - the recruiter is not your friend.