Thanks to Perrin's help on the cdbi list, and his code that makes Ima::DBI handle forking gracefully. I have my funky scheduler working nicely. It's currently dealing with over-running tasks (or rather it doesn't die, and complains about it a bit - exceptions and proper warnings and notifications need to be added), system constraints, limiting concurrent processes, etc.
The postgres hate is waning after being told some of the cryptic slash-x-y-f commands that mysql would name something sensible like show tables
The maypole frontend is working out of the box (from SVN), but needs the templates and stuff customised specific to the application, now to test it with the real systems and hope it works without problems for a few weeks before we go live at the end of march