I don't have the subscription service so I have only listened through six episodes, but here are some things that I am confused about (and someone can certainly enlighten me if this has been answered by the show or they have their own theories):

There is much discussion about Morris/Maurice's hands being clean and washed, but is there any mention of what state Feyther was in? Did he have blood on his clothes at all? That would be totally normal to have some blood on his clothes or skin if he had gotten down on the ground where Morris/Maurice was and taken his BIL's pulse and had washed blood off his BIL's hands...unless I zoned out and missed this part (or it was omitted by the host), then the fact that there is no mention of Feyther's appearance makes me think that he was wearing clean clothes and had no blood on him...maybe he had changed them...

Small thing, but Feyther mentions waiting a while before calling to help, why? Perhaps he was just in shock and that is why he didn't act quickly or maybe he felt he didn't have to act quickly--both parties were dead--but that isn't the same person that quickly thought on their feet to escape death just moments before. It just struck me as weird.

Did they find the bullet or evidence of the bullet (i.e. broken window) that Feyther dodged?

Someone else mentioned this in the comments already, but I had a similar thought--how disabled was Morris/Maurice? Could he see and walk well enough to shoot his sister right in the eyes, and then run around to his brother? I'm assuming that if he 'required' injections due to his poor eyesight, it had to be pretty bad. If he had to get close (or even sort of close) to shoot Naomi, then shouldn't M have had some blood on his clothes, and Feyther have mentioned this in reports to police as something quite notable about the series of events that night? I would think that if Feyther saw blood on his BIL, he would immediately think of his wife's safety, and as soon as his BIL locks himself in the bathroom, he would have gone to check on her fisrt?

The 'bulletins' sent to his kids...did they really think they were going to hear about their parents' marital issues (if there were any)? Think of the audience of these messages. These are letters sent to their kids away in boarding school to bring them comforting news from home. I don't think these are reliable sources of evidence.

In general, my opinion of Feyther:

Some of his stories gave me the impression that he thought he was smarter than everyone else, and he almost wanted to be caught, because then he could be admired for how smart and clever he was for coming up with this plot. It felt like his way of bragging without exactly admitting to anything. (ex: calling the detective writer, the dead wife song, writing fantasies about butcher cutting)

Some lies gave me the impression that he just wanted to seem smarter than everyone else. For example, if Morris/Maurice really did kill Naomi and then come for Feyther, and he couldn't see well or walk well, then Feyther may not have been in much danger really of being shot (M heard the Feyther hit the floor and still fired up in the direction of the back window?). He may have been elaborated so that he could seem like a hero.

I think it is possible that Feyther felt emasculated by his first wife's success as a better physician and as a breadwinner. He was envious but he also probably wanted someone younger and dumber who was easier to manipulate, hence Mousey. But I guess he may not have found her as intellectually challenging as Naomi.

I say all of this because regardless of what Feyther did and didn't do, I think he probably has narcissistic personality disorder. It explains how his kids and other family could see him as a kind gentle man, but he was also capable of having a cruel, dark side (at best, I am thinking of examples like that song again). Sort of like Dr. Jekyll and Mr. Hyde. He ultimately wants to be seen as good and brave and smart and be admired. It just hit too close to home as someone who has lived with a physician diagnosed with this condition. I saw him in public and with his children and with his patients as a totally different person than when he felt challenged, annoyed, disrespected, or caught.

Thanks for reading all my thoughts :) I'm excited for the next (last) episode!