New to Android and just looked at http://developer.android.com/reference/android/util/Log.html
My question is regarding everything except debug. How do these Log entries get cleared such as Error so that they don't consume space? Also, Is there a way that the logfile can be queried so that it can be sent to a central web service or something for quality purposes etc.?
Log space is a limited resource shared by all apps on the device. Newer entries push out older ones. You can read the logs if you have the correct permission, but this can be considered rude/borderline spyware by users since it will give you much more information than just what your app contributes to the log.
You can already get problem report data for Market apps as reported by the system: http://android-developers.blogspot.com/2010/05/google-feedback-for-android.html