1) Rethink the character limits
As such, I would completely turn things around. Instead of being able to play the fewest characters, I'd have them able to play the most. One noble per continent, including Beluaterra. At least for their first month, then force them to pause a character every week afterwards until they return to normal limits (3-4). And until that is reached, obviously they'd be capped at one character per continent, and not able to dump all 7 in the same one. Different continents have different cultures, different wars, different histories. The broader the net is cast, the greater the chances that they find at least one that suits them enough for them to stick around.
That might be a bit excessive. The forced pausing of characters they had been allowed to start seems pretty harsh. I'd rather start with a sensible character limit from the start.
2) Rethink newbie mobility
This wasn't my idea, but I think it's a good one. Changing realms should be made easier for newbies, so that if they land in a dull realm, they can try another realm without taking many weeks to get there. Add a new feature, "get smuggled out", which allows a character from a new family to get moved to a new realm within just a few days. One one hand, it'd allow them to try different realms if they fall on dull ones, and on the other, their increased mobility might incite older players to interact with them more, out of fear they'd move to a rival (instead of just quitting the game or staying by inertia).
That sounds like it could be a good implementation of that idea. If your account is under a month old, and you have spent more than three days in your realm, an option appears at the top of the Actions menu allowing you instant transport to another capital on that island where you automatically become a member of that realm.
3) Bring newbies together
...allow continent-wide OOC communication between newbies. Allow players who have been in the game for, say, less than two months to write to each other. "Hey, I'm in X realm, and it's dull, what are you all up to?" "Hey, Y realm is awesome, I was put in a senate group and I'm being considered as lord!" "Hey, the king here is totally vicious and badass!" and the like could help newbies make more informed decisions about where to play, by consulting with peers, instead of relying on the old guard's forum propaganda (if on anything at all).
May be useful, I guess. A prominent option at the top of the Messages page. It would probably need suitable language to point out that its an OOC channel for sharing game experiences, and not for sharing IC information/plans/etc.
I also still like the option of the island-wide OOC channel for mentoring.
