HEI Install Problems

I am correct in that the stock mopar ECU should be unplugged correct? The wiring over there shouldn't be connected with anything at this point anyway since the old reluctor connections and coil connections are disconnected.

You are correct, though it shouldn't matter if the new ECU has it's own power supplied, and is the only thing connected to the distributor.
Something is up because these modules are generally really easy to hook up.