Considering that everything he did to cover this crime up to make it APPEAR that he was being framed, nothing would surprise me. The reason all of these points seem so ridiculous is because he knew exactly what he was doing and had had 18 years to plan it out exactly the way it would look as if he was framed if he ever got the chance. And he did get the chance.
A criminal mastermind could not remove every trace of a homicide victim from his premises, which is asserted was the scene of the crime. Brendan also said he cut Teresa's hair. No hair, blood - nada - could be detected in SA's trailer, garage, clothing, furniture, or vehicle.
How could he perfectly plan that Manitowoc County investigators, who were supposed to be restricted due to conflict of interest, would find the suspicious "evidence" ???
With his known IQ deficiencies, I think you're giving him too much credit!