Hmm.. for the throne, try this perhaps...
void main()
{
object oPC = GetLastUsedBy();
object oThrone = OBJECT_SELF;
effect eVis = EffectVisualEffect(VFX_DUR_GLOW_GREEN);
eVis = SupernaturalEffect(eVis);
if(GetIsObjectValid(oThrone)&&
!GetIsObjectValid(GetSittingCreature(oThrone)) &&
GetPCPublicCDKey(oPC)== "Your CD key")
{
AssignCommand(oPC, ActionSit(oThrone));
ApplyEffectToObject(DURATION_TYPE_PERMANENT, eVis, OBJECT_SELF);
}
else
{
string NoSit = "You are not allowed to sit on this throne! It belongs to Brior!";
FloatingTextStringOnCreature(NoSit, oPC);
}
}