In so far as your question of being sued for slander is concerned, it is best never to publish any negative information about any client. It could lead to suits for defamation (slander & libel), possible unfair trade practices, etc. Even if you win, you have to go to the expense of defending. It opens the door to more trouble than you need.

In so far as negative allegations in court complaints are concerned, most states grant you a qualified privilege to make such comments in your court pleadings which will protect you. The privilege generally (depending on the state) does not extend to your publication of the contents of your court pleadings to the media. These pleadings are a matter of public record, and if the media chooses to copy them from that source and publish them, it is not your publication for purposes of a subsequent suit by the defendant for defamation.