The whole subject of capital punishment for heresy is exceedingly complex. They are historically derived from Hus and his movement, but somewhat indirectly. They actually formed about 300 years after Hus's death. I have never taken the Eucharist in the Roman Catholic Church. It is not my intention to disrespect anyone's church nor would I disrespect my wife or my wife's priest who has been very good to both of us.
Intercommunion presupposes doctrinal unity.
I'm happy to see that you understand that. Many don't - including our illustrious President. You are correct that the Missouri Synod did not support the signing of the Joint Declaration . Well, they labor under some of the common misconceptions of Catholics. But I respect their adherence to their own denominational traditions.