Good luck with multiple accounts - I'd give it a week till Facebook shuts them all down.

You don't need a separate account for business - you become admin of a business page, and access it with your existing account.

If you are this scared of privacy, I'd recommend skipping the couponing altogether - they'll get all the info they need off you one way or another anyway. The whole purpose of Facebook is that your primary account has everything in it - if you share things correctly, you will not need separate accounts for each group of people.

That said - given your concerns, I'd just stay away from Facebook entirely.