Where is the output of TextWriterTraceListener redirected?

To the Console or a text file depending on the parameter passed to the constructor.
How do assemblies find each other?By searching directory paths. There are several factors which can affect the path (such as the AppDomain host, and application configuration files), but for private assemblies the search path is normally the application's directory and its sub-directories. For shared assemblies, the search path is normally same as the private assembly path plus the shared assembly cache.