re: the DNA testing. Talk to your lawyer, but it may be posible to get a court ordered DNA test. It's exxy and all parties need to have their samples taken by a doctor or nurse for it to be legal, but you may want to consider it. If you do ever go down this path, you'll need to do it while your DD is a minor or a court may not allow it to be in the best interests of the child.

this is WA specific, but I think the Family Court is federal anyway:
Legal Aid - Western Australia