Lots of good stuff...

Torture
The problem with it is you get the answer you want. Ask a question, get an answer. If one does not like the answer insert torture here. Rinse, lather, repeat. Burt and Riley are sure Tardust knows. He could have easily have no clue and just told them where to find Durai's dad who is way more paranoid and a hermet with beaucoup de booby traps and shoots on sight.

Corpse Gas.
Damn, It just begs the question, is there something special about the people immune or disturbed by the gas? The most likely is that there is something special about Saul and Tanya. It may correlate with Keratin level perturbation. But, this is a small sample size and I am not ready to collapse this wave function.

Biodiesel
Damn, Burt. Forget about it. You would just be chasing another logistic supply chain. He is going to need Ethanol/Methanol and a strong alkali like sodium or potassium hydroxide. They would be much better off to hit the naval yards and find some prepositioned resupply nodes.

Hope The Reveal
I have always thought her vision would get better and she would recognize someone hiding in plain sight to pull the plot together. If we think about it, she has had very little time with Burt, although I "hope" it is not one of Ink's symbles that sets her off.

Saul
I learned a long time ago to never judge a man in his grief. But damn, Saul, you leave me perplexed...