You can ignore those DEBUG stacktraces. It's the way it's implemented. As for enabling TRACE levels, for production the recommended log level is INFO. So you shouldn't be running into this problem in production environments.
Yes indeed, but when you do need to debug, it's difficult with all those stack traces.
Since upgrading from 4.2 to 7.2 I've had to physically login twice to have a principal when I called create on a session bean. (I'm still using 2.1). Having tried everything I can think of, I've made my GWT code login twice. That works fine but obviously not a very satisfacotry solution.