You could make a separate small GUI app for the configuration (GConf can notify about key changes do your daemon can automagically react to changed configs).
Anyways, I would run the app in terminal in foreground while debugging, shorter way to a real daemon from there (and many of the daemons in linux/unix world have an option to start in foreground for exactly this reason).
on single user device like the N900 the privilege separation does not help as much as all the important bits for the user (user data, photos, contacts etc) are accessible/messable with the users privileges...