Interesting...so excommunication is handled at the parish level in the LCMS? If so, is it binding on any parish in the synod?
Yes.
If so, is it binding on any parish in the synod?
It should be. Unfortunately, some pastors can be a little lax about respecting an excommunication done by a brother pastor.
When I was pastor in Nebraska, our LCMS congregation excommunicated a man who dumped his wife to take up with another woman. What did the guy do? Joined the ELCA congregation down the road.