All:
Thanks for the input for query layers. I have successfully created a query layer, mxd with relate (parcel feature class to ownership query layer), AGS service, and AGS application. I was very happy to see that the relate was honored in both the AGS Service (and REST), and in the OTB web application. I tested query tasks built on the query layer in the .net app, and was pleased to get results. Also, using search attributes task on the parcel layer with the parcel-ownership relate returned the linked results. KUDOS ESRI for finally giving rdbms capability to AGS!