Yes, you can still be sued, because you already broke the original contract. They are not obligated to take payments by now..but, if you make payments, that shows good faith, and if they still decide to sue, which they may not, then at least you can show the judge that you tried. It looks good for you, and the judge will most likely say that you can just continue with the payments you are making. But, just because a law firm has your account, does not mean they intend to sue. They may decide to send it back to the original creditor, who will then send it to another collection agency. That law firm may not even be licensed in CA, did you check that? You can find that out from the CA attorney general I believe. They have to be licensed in the state they are trying to collect in, because if they take you to court, they have to come to a court in your area, not where the law firm is.
You can read up on collection laws on ftc.org, you may want to do that.