Can a paternity test affect child support and visitation

by Very Confused Man
(Tampa, FL)

I am a dad going through a divorce at this time. My wife I believe conceived a child when she stepped out of our marriage. I love this child very much and want her to remain a part of my life. I have been advised by my family and friends that I should obtain a DNA test because she can keep coming after me for child support every three years. (she is the kind of woman that wouldn't miss a year or opportunity). She is now pregnant with yet another mans baby. I fear that because she chooses not to work that she will attempt to hit me up for more and more child support as often as she can.

I am pretty sure that the DNA test will come back in my favor but I don't want to lose the child's visitations. Is there anything I can do? And if I suspect I know who the biological father is can the courts make him get a test? He's under the assumption that they can't and that he is getting out of this situation scott-free. My name is currently on the child's birth certificate. Would that remain or be removed and would the mother be able to change her last name? The x-wife lives in North Carolina so we now have to follow that states laws! Very confusing!

1.) How will a DNA test affect my visitation with a child?
2.) How will a DNA test affect my child support even if my name is on the Birth Certificate?
3.) Can the courts order a DNA test for the suspected biological father?
4.) Is there a cap on Child Support?
5.) Can the mother change the childs name, if i am found to not be the father?