So, are your stepchildren making these allegations? Or are they refusing to give you the source of the allegations? Parents of an x are not exactly a neutral third party. Also, when diverse allegations are thrown at both of you on unrelated incidents, it gets REALLY shaky. How can they find this case "founded" with virtually no evidence? How did the psych evals go?
I can only tell you that my experience was much different. My daughter accused me of abuse in order to switch custody, after I put her in drug rehab against her will. She recanted about a week later, so the case was only open for a couple of months.
On the flip side, although my daughter has been very open about the fact that her mother and stepfather buy pot, beer and cigarettes for her, DCF has taken no action at all to keep my addicted daughter out of that environment. I also reported it to CPS in my x's state, and they did nothing either. No criminal or protective action at all.