"Married" Oct 2002 Separated May 2003 He gave a false name for the marriage certificate It Was one of four names he uses. Am I legally married?

ANY question on law needs to include your general locale as laws vary by area.

Most likely not, but it could depend on local laws. But it should be easy to get an annulment. You wouldn't need a divorce.

No.If your man name is John Thompson and he put Steve Thompson,you are not married to John unles he changed his name to Steven... but with last names just the same... unles he took another side of the family name... (Jhonson instead of Thompson... )

Actually yes you are legally married, it will be easy to get it annulled or over turned, but until you take it into court and have the marriage license declared not valid, you are still married.