“The shock associated with the defeat led to a zealous effort to identify and understand the extent and machinations of this interference and to discover whether the Trump campaign was in any way involved”
Bunk. They knew damn well Trump and his people weren’t involved. How could they be? They were the ones who started the hoax in the first place in the summer with the Steele fabrication.
You are absolutely correct about the illicit FISA warrant and associated surveillance.
The Flynn case, on the other hand, is built on legitimate surveillance of Russian ambassador Sergey Kislyak. Flynn's communications with Kislyak had nothing to do with FISA warrants. There is no FISA warrant needed to intercept communications of a foreign diplomat.