On Cascade Profiler, can you run a traffic report that shows all traffic from inside...

No, this cannot be done with Cascade.

Set up the query to ask for all hosts between: Hosts "Within" a group "ByInternalHosts: All" (where All is a host grouping containing all inside address space) and for Peers set to "Outside oF. ByInternalHosts:All".

Configure query as B above but also add the Proxy Server to the "Outside" list.

Configure query as B above but also add the Proxy Server as a "not" in the Traffic Expression field. The expression to add would be "not host proxyhost " where proxyhost is the IP Address of the proxy.