Your conclusion that Clapper lied begs the question if he knew of the specific FISA warrant. He was DNI, not Sec/DOJ or FBI director. The DNI isn't going to know about FISA warrants on a regular basis.
As for your assertion that the proof required for FISA warrants are a joke, that's not really true. Comey has anecdotally stated that the proof in documentation is 'thicker than his wrist' and
https://www.justsecurity.org/38422/aint-easy-fisa-warrant-fbi-agent/ this outlines the process.
I'd suggest that the Freedom caucus has no idea about this process.