Re: the question of whether or not KK ever saw KB's body.
I suspect this is one of those things that KK may or may not be telling the truth about. I can't see any way anyone except PF could challenge her on this, because as far as we know now, those are the only two people who could have seen KB after she died.
At most, it will come down to 'he said, she said' if PF claims she did see KB's remains.
Re: discussions about KK's driving routes - and the cameras on some routes.
IIRC, KK made a number of trips to Florissant before the three murder attempts. I don't know about you folks, but if I drove the same 800 mile trip multiple times, I'd probably settle on one route. I probably wouldn't change it up much unless I was visiting someone on the way or there was bad weather.
It seems to me that KK not only switched up cars (IIRC, she rented a car once, borrowed a car on another trip), she also switched up her routes - to avoid cameras?
I don't think she was just being cautious because of LE or her husband. I think deep down she knew that if it came to it, PF would sacrifice her to save himself without a second thought.
And personally, I'm at the point now where I don't think he particularly cared if she got caught. I wouldn't go so far as to say I think he was setting her up, but I think his original plan involved her doing all the dirty work. If KK had killed KB, PF didn't need to worry about disposing of the body - that would have been KK's problem.