A custody agreement and danger?

Me and My ex do not care to stay together anymore . We have (2) kids and not married . She sign’d over her parental rights of her other child .
Now , she wants to take both kids with her . I feel as if she is not responsable enough to do so . She wants to write up a agreement stating such.
I myself , do not want the hassell of dealing with issues that she exsposes them to . She has stated that she would not take me for child support .
What type of paper work should I persue in this event to make it legal . And , what would be a violation of what we agreed to do . Therefore , under
violation of that agreement I will get full custody of my (2) kids . I have been self employeed for 20 years. She just started working this year since our
(2) kids. We split for 4 months at one point. In which we where going to court . She found someone else during that time (2010-2011). Being the enviornment
my (2) kids where in , I told them to move back in with me. The other half she found was violent and she put a restraining order on him . So, we was out shopping
one day and he ran up on me , her and my daugther. My son was born Nov 17, 2011. She does social networking. So I find out this year (2012) that the same guy
was one of her friends (Dec 28, 2011 ) on this social network . She was all calm like it wasn’t a big issue . I fear for my life and my kids . What can I do ?
I would like to hear all opinions please . Thank You Very Much .

Custody can be put in a court order or in an agreement. When it is in a court order, you have enforcement power of the court for contempt issues and can file motions to modify custody based on a substantial change in circumstances once a permanent order is in place. If you wanted an agreement changed, you would need to file a new action for custody. There are pros and cons to putting custody in either a court order or an agreement and what is best for each individual varies based on the facts.