Sounds like an awful lot of work for the Devs with lots of room for people to find ways to abuse this new "caste".
If people truly want the ability for a second "noble" type character on each continent, there are simpler ways to accomplish this.
First and foremost would be restricting both nobles of the same family to the same realm.
This would prevent spying and other such activities because both characters would/should share the same goals.
The elder of the two would have the current standard benefits of a noble.
The younger (maybe only available by working though the adventurer class to earn his nobility) could have many of the restrictions proposed by Chenier.
Can not hold any govt positions lordships etc, reduced income for them, limited to half-size units, only access the basic warrior class.
If the elder of the family decides to change realms, it is a family event that includes their younger member as well.
Essentially, the elder member speaks for the family, votes for the family, represents the family's interests...
While the younger is limited to being a warrior of the same realm.
Should a player decide that the younger is more fun to play, they can always retire the elder family member to make way for the younger to move up. Maybe even have an option for the younger to poison the older sibling to make way for his progression up the ranks.
