Why did WA cooperate and (apparently) without a lawyer present?
That's a key question. Either she was completely innocent and knew that she had nothing to hide, or she was especially confident in her ability to mislead LE and wanted to appear cooperative. Now after having seen this video I suspect that she did not know for sure that a plan had been formulated and put in motion, because I think it's unlikely that she would have cooperated otherwise. In other words, I don't think she would have cooperated if she had been told in clear and express terms by CA or DA that they had hired people who would be carrying out a murder on her behalf. I've had trouble believing that CA/DA would have planned something like this without WA's buy-in and express approval of the plan, but for me this video calls into question that idea, at least for now without more information.
But, it also appears possible/likely based on her comments in the video and in the Tallahassee Democrat story that CA and possibly other family members may have given her reason to believe that they might have been contemplating something like this, at least in a general sense. As others have mentioned, it's telling that her first reaction was to wonder if someone had done this to try to help her, or out of "anger" at Dan. Out of all the reasons that "shootings" occur in homes, targeted strikes carried out for the benefit of ex spouses would seem to be pretty far down on the list of possible reasons, following "home invasion/robbery," "suicide," and "accident" and probably several other categories. So it seems like a tell regarding her previous conversations with CA and maybe other A's that her first response was to wonder about what would seem to most people be a long shot reason for the "shooting" mentioned by the investigator. Also a tell that she expressed relief that DA seemed surprised. The question then just becomes exactly what did she know and when, which will probably be one of the hardest things to prove unless LE has struck it lucky with their investigation somehow. IMHO, just speculating as always.