I'm mostly an idiot, as I managed to get an example working, but in that vein, I have a few questions.
1) The RESTeasy doc seems to say that the Application class is optional. I had been putting my classes into a .jar and then into the resteasy.war/lib folder. But I forgot to do "singleton.add(MyClass())" in Application. I'm guessing that since scanning wasn't on, the only way for RESTeasy to pick up my class(es) is to use Application in this manner.
2) It seems the Application logging ends up in stdio.log in JBoss, RESTeasy seems to send it there via STDERR. Did I misconfigure something in JBoss' log4j or is this normally where it goes? I had been looking for some "sign" of my services/annotations getting scanned but it was hidden in here.