Well, i have a solution to the ''new players'' problem.
Limit the number of Houses/realms/landgrabbing powers to a certain amount, or at least, restrain their creation from now on, or apply rules concerning Houses such as the fact that from now on new Houses are considered vassals of an already existing faction following certain conditions and whatnot.
Honestly, if you were, for example, to leave only three major human factions, such as the Engems, Kingdom of Hierax and Skyrim, well, i wouldn't mind that much to lose all the work i've putted into my factions and groups, as long as I am promised to have a more dynamic world with bigger factions where people actually do interact diplomatically and militarily.
In short, make new players join existing groups instead of letting them start whatever they want whenever they want, so we don't end up with the current situation, a world full of tiny factions and groups that don't have the resources to actually do anything and are left to RP claims out that they will never interact with anyway.
Lemme tell you, I remember the times when Lonmar was fighting the Federation for the crown. At that time, there were only 2 big factions with dozens of players and multiple regions, (with several smaller ones, but that's alright), and the world was a dynamic and worth fighting for place.
Heck, im kinda hating myself a little over the fall of the Arcturian Empire.... It was really becoming a proper faction with real power, as we had over 7 regions, and something like 3 vassal houses, not including the engems.