How does succession in Tuthina work?
Succession in Tuthina is (usually) based on a system that resembles elective monarchy. The imperial harem of the former emperor will/should leave a lot of offspring between him and his wives, which involves almost all land-ruling nobles in the realm. When the emperor passed away, one of his offspring will be appointed by the imperial court as the new emperor. While the appointment is theoretically based on the ability of the candidates (namely anyone who bears the patrilineal imperial lineage), in effect it usually means appointing the one that receives the most support from the most powerful nobles (usually those that also share the noble's (matrilineal) lineage).
Those who are not appointed will either stay in the harem, or be appointed back to the lands of their original lineage and intermarries with them again, so that in the long run, more nobles will share the imperial lineage and reinforce the coherence of the empire. Female ones (as they do not have the lineage, and thus usually invalidated from succession unless there are no other choices) also tend to be sent outside as diplomats with other nations. This is due to the fact that we do not have the concept of embassy, and thus interaction of nation-to-nation level will need someone from the imperial family to conduct, before the central government can do any meaningful works.
What are the views on foreigners in or outside of Tuthina?
Most Tuthinans bear an inherent distrust towards outsiders, especially after the Tuthinan Republican Uprising about half a century ago. The distrust is based on the idea that as Tuthina has an unique culture, and culture itself is the ultimate embodiment of how the people believe the world is/should, people who has a foreign culture (basically every foreigners) are more or less incompatible with the native way of thinking, and thus communication, understanding, or even a common ground for negotiation would be very difficult, if not impossible. Lower nobles also share similar thoughts, as the feudal system of Tuthina is built upon the common framework of a hierarchal socio-political structure. Those outside the structure usually cannot understand it, and thus having a power struggle with them in the traditional way will not work. As such, the local rulers tend to use all their means to eradicate any potential foreign power in their land before they grow too large.
Of course, there are exceptions to that. The most obvious one would be people of foreign origin that adopted the Tuthinan culture, or at least have a decent understanding of it. Because the reason of distrust is based on the incompatibility of cultures, once that is sorted out, the origin does not matter. Another exception would be higher/well-learnt nobles, who have enough knowledge and training to ignore the differences and focus on practical diplomacy. If all those fails, there is a profession called the
Compradore. Their job is to serve as the middleman between foreign business and native business, and thus translate their culture into the Tuthinan culture to ease the cultural conflict. They probably do not come cheap, but costs less than the combined tariffs that would inevitably emerge otherwise.