Just an update, both myself and my wife were approved recently.
Did interviews in JFK, was quick and easy.
Before i applied for my wife i read the whole thread as i was very unsure of what info to put for her last name. The only document with her maiden name is her passport, which expires in 4 years. All other documents have her married name. After PMing a couple members (thanks) I ended up putting her current legal name on the application and in the section under "Other Names Used" i put her maiden name.
When she came to the interview they edited her name in their system to reflect her passport/maiden name.
In hindsight i should have done the other way around, but i think either way you do it there is nothing to worry about and they wont deny your "conditional approval" because of this.