Very selective commentating.

"Ecclesia is mentioned only twice in gospels. A latter insertion?"
1. I guess you meant "later" ... 
2. Selective:
a.  you ignore its occurrence in the letters of Paul, which all predate the Gospels ...
b. you ignore its use in the Acts of the Apostles, which is contemporary with Luke's Gospel.

Your typification of Brown is shallow. If you really want to call him an "archaeologist", then please recognise this as a valid science, revealing valuable insights.

You, on the other hand, sound like the one scrabbling around ...