Afraid ex will run with my daughter

Not only has my ex left my daughter alone, interfered with our (my daughter and my) relationship, neglected her care, etc., he has also not paid on loans that are still half in my name (he never refinanced to get my name off). One is getting fixed, but the other is a mortgage in which they are threatening to foreclose his home. We have joint custody for now and are in the beginning stages of a modification for custody suit. My credit will suck, but my main concern is him running and taking my daughter.
I do not have solid evidence, but he is sneaky, has taken her out of state and lied to me about it, etc. I am scared. Please tell me that this lack of responsibility can be a factor in our lawsuit, and also, what can I do for now??? He has nothing holding him to NC except this soon to be foreclosed house. When it gets foreclosed, it will be too late, he will be gone. I already have trouble locating him now. Please help!!!