Before I was out, I had two accounts: one for my male persona and one for my female persona. The Facebook police don't like it, but they don't actively seek out people with multiple accounts. They only respond to complaints.
The thing about having multiple accounts is that it is very hard to keep them separate. You need to access them from different machines or at least from different browsers on one machine. You cannot ever have any friends in common, not can you like the same pages or be members of the same groups. Don't use one identity to look at the other identity. FB keeps track of that kind of thing.
What you need to avoid is FB suggesting your new identity as a potential friend for people you know under your old identity. If it finds anything in common, it is likely to expose your two identities as people who know each other in real life. The risk is if friends see pictures of your other identity and make the connection.
So you have to be totally paranoid that you don't accidentally make a connection.
