To your points: Spoiler 1. I mostly agree but I feel like all modern TV either overuses surveillance as a plot point or completely forgets it exists. Also having a prophetic character can easily destroy a story -- they must have mysterious reasons for not just solving everyone's problems before they arise. I don't think this one will be addressed in the future. 2. This entire sequence was [I have to believe intentionally] dream-like. The characters' emotions have been manipulated to the point that they are not operating logically. This plot point will probably be a big part of season 4.
Rather pointless, but in the finale I had a moment of "Wait, why is the evil lawyer (Wallace Shawn) wearing a priest collar?" Then I remembered he played that on their other show "The Good Fight." I suppose for people who haven't seen "The Good Wife" they'd a surprise out of the character that Mike Colter plays on that show. It is fun certain actors appear in multiple shows by the show creators.
One of my favourite show. One of the few in the horror genre that actually gives me the creeps. I may have to do a rewatch before the next season starts.
The Following (starring Kevin Bacon), which was on FOX from 2013-2015, was pretty damn dark. Bacon played a FBI agent fighting against a cult of serial killers led by a charismatic sociopath. Bacon's character also had a dark side.