Good theory, and perhaps true, but I'm open to the idea that other theories have credibility as well. Seidel/Ennis seems so simplistic.
Then again, someone brought up a really good point elsewhere. Perry Mason is good at uncovering the truth - which may not always get his client off. Or something like that. This person also speculated that we may not see an ending that answers every question as sort of a live-and-learn moment for Perry.
My feelings are that minimally, he'll clear Emily of murder but maybe not kidnapping. He may not be able to prove in court how Charlie died or who killed him even though he has a general idea at this point. Ennis could walk scott free.
I still think there could be a mastermind above Seidel. Someone threatening him to raise the money or they'll turn him in to the cops. This person would have to know that Baggerly is Mathew's father. Baggerly said he kept this knowledge from the elders/church, so who could that be? Barnes managed to figure it out rather easily, so I suppose others could as well.
I also think the thread will come into play this final episode and tie (no pun intended) a bunch of pieces together. Someone said they would like the ending to circle back to the very beginning where Perry decides to pursue the case and says "So...you like turtles". If this happens, it seems we should then learn about the origin of the thread. Charlie's baby blanket in the crib had turtles embroidered on it so maybe it's an embroidery thread. Alternatively, it could be a taxidermy thread picked up at the Los Angeleas Alligator Museum perhaps.
I dunno. This could go in lots of different directions, that's for sure. I just hope the ending is interesting :).
Oh, and two other lingering questions that I hope are answered are 1) why Birdy and Alice drove all the way from Saskatoon to the states. Did they start in Missouri where the Baggerly's originated and move west to California? 2) the nature of their relationship and "adoption".
This show started of so poorly for me for lots of reasons, but the characters, cast (perfect cast across the board, IMO), and period pieces kept me going. As things went on, I've appreciated the story telling a lot more than I did early on. It's actually grown to be pretty entertaining for me and I'll need something to replace it!