Anne,
I like to set everything to WARN or ERROR by default in order to keep the log files as clean as possible. I also will turn off the mxe.mbocount system property by default, and only turn it back on if necessary for debugging.
As for the PMWoGenCronTask specifically... it actually uses the maximo.application.PM logger more than it does the actual cron task logger. Set that application logger to DEBUG and you should get more information in the PM Generation log file about the routine, such as the specific SQL used to pull records. Please note that this log file is specified in the cron task parameters and is separate from the standard Maximo logs.
Hope this helps,
Alex