Hi Yantor,
Currently, there isn't a way to set a site-wide default for the "retry" values.
If the Qube GUI is being used to submit jobs, then each user can save his/her
preference as the "default" for the jobtypes they use.
For example for Maya, open QubeGUI, then "Submit > Maya Job..." then scroll
down to the "Detailed Qube" section, adjust the "Retry Subjob Process" (or
"Retry Frame/Work") value, then hit the "Set Defaults" button at the bottom.
The next time you bring up the dialog, the box will be pre-filled with the default
value you provided.