After pulling all the circuit breakers, I applied power to the avionics panel for the first time this morning. As needed, one by one, I started resetting the breakers. So far - everything seems okay. I did not reset any breakers on any circuit that is still open and/or requires work.
Following a suggestion by fellow builder Randy B., I used a heat gun to test the CHT probes. They all worked. I did notice during that test that the EGT probes indicated a temperature increase too. Probably from blow-by of heat on the exhaust manifold while testing the CHT. Nice – two tests completed at once.