Legal Question in Credit and Debt Law in California

"I don't want to file affirmative defenses that won't hold in court until I know what info the attorney actually has"

The information about your debt should have been already alleged in the complaint. Unless this is a highly unusual debt, but if it's a typical consumer debt (like a credit card), I can't imagine the attorney not leaving out details about how the debt was created and incurred by you, especially with a form complaint in a limited civil case. And that's most likely enough to plead a case so that defendant has to answer next. My opinion is that I doubt if your bill of particulars will get useful information more than what's already in the complaint. As far as getting an extension to answer, you have to file a request in the proper format with the court.