Looking at player densities where I play, East Continent is pretty good but that's about it. Beluaterra is pretty fun to be in right now but the south is completely unplayable - only the northern two thirds allow for a relatively balanced game and this has skewed player densities massively. Dwilight has poor player densities made worse by a disproportionate number residing in Luria Nova. The Far East is generally good apart from two pocket realms which have pretty much 1:1 noble to region ratios. I don't know about other continents.
But it does seem to me that the best ratio, game-play wise, is a ratio of 3 nobles to a region. However, there aren't any realms (other than one region realms) which have anywhere near that ratio.
Put bluntly, the player base is too low - closing a continent is one way forward but, then again, the geography of several of them channels them into fixed patterns, many of which aren't good for gameplay.
The geography of Atamara forces realms into essentially the same areas (apart from the realm names much of Atamara looks very similar to the way it did when I first started playing the game) but it's large enough to have balanced conflicts - the only problem it has is the players who've sewn it up under almost total Cagilan Empire hegemony.
Beluaterra has great geography north of, say, Fheuvenem but the south sucks for having sustainable conflict.
The Colonies are great in terms of geography but obviously have the one turn a day thing.
Dwilight sucks geographically - the player base is too low and a combination of travel times, history and geography have rendered the north pretty doomed to stagnation. The south is where it's at but the large gap between Fissoa and Giask-Shinnen basically distorts things and guarantees a regular powerhouse where Luria Nova currently is which will be mostly untouchable by its neighbours. Split up Palm Sea into some more regions, throw a city in the middle of it and maybe reduce the population of Askileon and Giask, however, and then we might be talking...
East Continent largely works but it will inevitably lead to north/south alliances and wars due to the terrain. On the other hand, the way it's divided up into regions works much better than the Far East where you have more than one chain of cities/strongholds adjacent to each other.
For the Far East see what I said about East Continent.
Now if it was me I'd say you could tweak the geography of southern Dwilight and sink the north of it, you could sink the south of Beluaterra, you could keep FEI, Colonies and EC the same and you could nuke Atamara (trolololol). That still wouldn't fix the player base issue though so the best would either be a big geological upheaval which forces continents together while sinking part of them or locking some continents and giving players a small window to evacuate to a neighbouring continent.
