Please understand that the policies of Just Answer, as well as the practical limitations of any online site, do not permit us to "recommend" what you should do. With that limitation, I would suggest the following....
CPS is a difficult entity, their employees are overworked and underpaid. So, while their mandate is wonderful (the protection of our children), the facilitation of that process is terribly flawed. It has been my experience that their employees will, shall we say, "fudge" the facts to fit the circumstances.
Having said that, I just don't see a viable lawsuit here. While the workers actions are certainly questionable, I don't believe they arise to the level of actionable.
I typically tell my clients to cooperate with CPS, for so long as it makes sense. For example, if there is an allegation of drug use and you have no drugs and use no drugs, you should permit them to enter your home for an inspection and to take a urine sample for testing. However, if they come over 4 or 5 times to do the same thing, at some point, you need to withdraw your cooperation. I would suggest that you may be at that point.
It seems as if CPS may be on a fishing trip with you. If so, withdrawal of your cooperation may be the best remedy. If they don't have cause for a removal, then you may be able to put an end to this case by ceasing your cooperation and moving on with your life.
I hope you found my answer helpful. If so, please click on the green ACCEPT for my answer. This is necessary for me to be paid for my work and so that I can get credit for assisting you. Your question will not close, and you will still have the opportunity to follow-up if needed. Leaving a bonus and positive feedback is not required, but doing so is certainly appreciated! Thank you and good luck!
Also, several customers have asked how they may direct a question to me in particular. If you specifically want me to assist you in your legal matter, just put "FOR JOSEPH" in the subject line and I will gladly pick up the question as soon as I am on-line.