Firstly, the level name to use is FINE, not DEBUG. Let's assume for a minute that DEBUG is actually valid, as it makes the following explanation make a bit more sense...
In the Handler specific properties section, you're setting the logging level for those handlers to DEBUG. This means the handlers will handle any log messages with the DEBUG level or higher. It doesn't necessarily mean any DEBUG messages are actually getting passed to the handlers.
In the Facility specific properties section, you're setting the logging level for a few explicitly-named loggers to DEBUG. For those loggers, anything at level DEBUG or above will get passed to the handlers.
The default logging level is INFO, and apart from the loggers mentioned in the Facility specific properties section, all loggers will have that level.
If you want to see all FINE messages, add this:
.level = FINE
However, this will generate a vast quantity of log messages. It's probably more useful to set the logging level for your code:
your.package.level = FINE
See the Tomcat 6/Tomcat 7 logging documentation for more information. The example logging.properties file shown there uses FINE instead of DEBUG:
...
1catalina.org.apache.juli.FileHandler.level = FINE
...
and also gives you examples of setting additional logging levels:
# For example, set the com.xyz.foo logger to only log SEVERE
# messages:
#org.apache.catalina.startup.ContextConfig.level = FINE
#org.apache.catalina.startup.HostConfig.level = FINE
#org.apache.catalina.session.ManagerBase.level = FINE