Hey everyone, I just read the mission rules because I apparently missed it earlier. I thought I would take a moment to explain what seems like Random placement to various house properties on different worlds. In fact, it is not random at all, it took me almost 6 months to read through all of the fading suns lore, and what is amazing about the books they are very detailed about the location of all noble, church, imperial, and league fiefs and properties and even explain why they are there.
Anyways, the game starts 450 years after the assassination of Emperor Vladamir Alecto, in that time and even before the noble house intermarried and thus fiefs and other properties where exchanged in dowries. Remember these are entire worlds governed by a feudal system so minor lords of all the houses are spread throughout the Known Worlds.
So they are not really missions or embassies although they can serve as such. I don't think diplomacy with other houses should not be limited by the mission rule because in reality they all interact and conspire between their Embassies at the Imperial Court on Byzantium Secundus because they are required to keep ambassador there.
I think a simpler rule would be that a player cannot use diplomacy unless they keep a noble on Byzantium Secundus, and if their noble dies there then they can only communicate with other Nobles Houses that have fiefs on their worlds. Since, the lesser noble that owns the fief can speak on their distant cousins behalf.
Any thoughts?