first of all, the idea of a supreme court is a good idea. ( just like the international supreme court in Den Haag ) - and it can fail with just the reasons the Den Haag court fails. - that is, there are parties/factions that simply do not participate. some of them are minor powers - but some are major ones like the USA. if one faction does not participate - the whole aparatus of legislation turns into a true comedy - cause there might be some to decide, but none to follow the decission.
when its about sirius - the whole sector is a simplified model of waaay too different factions. it is an achievement that not every faction is at open war with its neighbours. law enforcement is worse than medieval. ( well, now we have at least a prison - but players cannot send a player to prison for roleplay violation ) there are multiple violations to the law - and only one punishment, which is death.
the question is - what can a court decide. national politics? - those are made by the various factions allready.
settling hostilities - thats a tough one, cause hostilities are coded.
starting hostilities/wars - see above, a court cannot make NPCs to start a war and alter faction relationships.
why does it work for the zoners ( to a certain extend ) - cause the zoners are one faction - and especially one faction without really pressing matters. the zoners have no issues to alter the face of sirius - decissions are rather on a small scale level.
if rheinland and liberty sat together, it might end up in a war - but that cannot be reflected by a pure player decission but must be done by igiss. even enforcing the nomad ban by the [SF] in bretonia is problematic. most players don t know about it - and no one really cares. - and that is only a very small political decission.
furthermore, decissions with such different factions presented in freelancer take long, sometimes too long to keep the original intention in mind. - as a matter of fact, pretty much all issues are solved allready in a court ( forum ) ... doing that in a roleplay way would be nice, but won t add up to the ingame-depth, i think.
a way to do it is .... ( and only if EVERY faction has a representative there )
form up a court - aswell as forming up a faction that must be : active in numbers and capable of dealing with a whole nation in case there is a violation. so if there is a decission against - lets say liberty... and liberty announces that they will not follow the decission, the supreme law enforcement must have the power to enforce it - hard to do, cause it requires a faction that is stronger than any other ( doesn t necessarily mean to be stronger in firepower, but can also mean by discussion )
anyway - a lot of work for something we allready have.