Ideas I'm a fan of:
Increased rogue spawns
Pro: Their effect depend on players' effectiveness, as organized realms will survive better than poorly-organized ones.
Pro: By turning regions rogue, they force theirs inhabitants to seek a home elsewhere, thus raising the noble density in said regions.
Pro: Players can choose their priorities and decide what to defend and what to abandon, it isn't decided arbitrarily by GMs.
Pro: It grants players some control over their own fates.
Con: Could bring back a higher PvE element on islands where it is brought as some characters will inevitably make it their sole purpose to fight the rogues (good for them if they like it, though, imo)
Con: Could distract and disrupt ongoing or pending conflicts (no worse than closing or freezing islands would)
Multiple lordships
Pro: Allows lordships to be given to those who actually care for them (I find pretty much all lordship elections to be very depressing, considering how the candidates never really seem all that interested in winning)
Pro: Would allow a higher title concentration, thus increasing the number of people without titles
Pro: Because of the higher title concentration, those wanting lordships would need to actually make an effort to get it (because all of the people who care and who are already lords wouldn't be excluded) and value is returned to the title
Pro: Successful low noble density realms would have more opportunities to continue expanding for as long as their success allows, increasing noble density in the realms they take regions from.
Con: Would require appropriate mechanisms to prevent some large realms from being turned into 1-ruler/1-duke/1-lord realms.
Con: Would reduce turnover (which is kind of the point, given how its too high and makes titles pointless right now)
Con: Being a simple knight gives people less to do overall, so it'd take away things to do from more people (but that's also the point, as a higher noble density, and thus more knights per lord, is what's being saught)
Continental merger
Pro: Realms on the edges have long been isolated from everyone, by putting the continents close to each other and reachable by sea zones, everyone would suddenly gain a number of new neighbors.
Pro: Continents lost, for example by increased rogue spawns, could still be reachable by the nobles that used to live there but that were forced to move away. Intercontinental coalitions would become possible to fight off any NPC invasion (be them scripted or otherwise).
Pro: On continents where there is a diplomatic gridlock, it would open up new possibilities
Pro: By reducing the number of realms that have almost no neighbors and almost no venues for war or other interesting activities, player retention should be improved
Con: would require a massive overhaul to the DB and to various mechanics
