afaik a addrating -10000 will make a unit enemy to everyone, also for same side so AI controlled units will fire at you. This is used in DM maps.
A way around this might be the use of all 4 sides OFP offers (west, east, resistance and civilian).
If you like to use lets say east units for the civilian side, this trick will help you:
create a high ranking Civilian with probability of presence 0%
then create your "Civilian side" east units and group them with with the civilian unit. this will make them all civ sided.
About the correct use of "setflagside" for resi side and civ side i can't say anything...maybe someone else?