ROB, concerning your approach to halacha that one may do what they are comfortable with, see Chazon Ish Yoreh Deah 150, 1 and 4. I don’t know that anyone disagrees, certainly not to the basic approach, but this is a famous nareh makom.
To summarize, you’re wrong. It’s not a hefker free-for-all once we don’t have a Sanhedrin.