My personal opinion on this whole topic is:
1) KC reminds me of a monkey who swings from branch to branch, never letting go of the last branch until she has firm hold on the next one. (ie: date one guy, start dating the next, then dump the last guy once she is sure the second guy is firmly within her grasp)
2) If Caylee had not died but had been found seriously injured or neglected, Child Protection Services would have pursued the paternity testing of any potential bio dad, but since the child died - the State would see no reason to pay for the expense of paternity testing as there is no longer a child.
3) I doubt the bio-Dad could ever claim "wrongful death" law suit, since he never established a relationship with the child, he is not deprived of something he never had.
4) My personal opinion is KC knows exactly who the Dad is (probably at least 1 of 3 guys) but her own Narcissism kept her quiet on the subject. I feel KC felt the bio Dad was not "up to par" for her to have a lifelong relationship with (ie: co-parenting of Caylee). I think this is a continuation of the denying the pregnancy; she can still deny the one-night stand or the relationship (whatever it was) because the Father of the Baby (FOB) was not good enough for Miss KC to admit to sleeping with and having a child with.
4) By telling everyone that Caylee's Father (FOB) died in a car wreck, she essentially painted herself into a corner since she couldn't hand Caylee over to Bio-Dad when she needed a break, money, etc.
5) KC had enough trouble answering to her own family about her actions, imagine if she had yet another family (ie: FOB's family) to have to answer to about her parenting.
6) KC couldn't handle anyone loving Caylee more than her (ie: CA, JG) so seeking out the FOB would only ensure Caylee was loved more than KC
7) Sadly, the very thing that might have saved Caylee's life (a safe place to land @ the FOB's family who probably would have cared and loved her, far away from the A's chaos circus) was never offered to this little girl. Caylee's life was only valuable when it met KC's needs, and she got tossed aside like a used prophylactic when she was no longer useful except to be a tool to hurt people.
IMO