I must agree, this does look really cool and have the potential to easily become one of my fave civs, too.
Just one thought - the Kuriotates might have severe difficulties once they end up in wars. Consider this scenario:
Player with eight cities produces two military units in each city and then goes on to build buildings for the next couple of turns. One unit to attack, one to defense. Eight offensive, eight defensive units produced total.
In the same timespan, the Kuriotate player capped to three cities likewise produces two military units in each. One to defend, one to attack. Three offensive, three defensive units produced total. This means that the bigger player has almost three times as many units - if the Kuriotates want to ensure that the other won't decide to invade, they must spend several of the next turns to build (at least) more defensive units to compensate for the difference in cities. In the meanwhile the other player isn't even breaking a sweat and improves his infrastructure by constructing buildings in his cities, and after some turns will idly instruct his cities to again build a new batch of units without it affecting his empire much - at worst, just when the Kuriotates finish building troops to make up for the *last* batch of new units. Even if the situation wouldn't be this bad, over the turns even smaller differences accumulate. Imagine a Bannor player with eight cities *and* the Crusade civic in effect... the Kuriotates being forced to constantly build their military in order to just survive doesn't really fit their builder flavor. (Might not necessarily be a problem at lower difficulties where the AI is pretty toothless, but much moreso at higher ones - or against human opponents.) Plus it might force them to play as a defensive player, period - while I do prefer to mostly just be peaceful and not fight very much as a builder player, even I do want to wage at least the occasional war at times.
Of course, I haven't actually played any games with the New Kuriotates yet, so it could be that the increased production in their cities makes up for this. If not, two ways to help avoid this might be:
1) Scale the amount of cities allowed to the Kuriotates to the map size. Only being allowed three cities isn't any sort of a problem on a Duel map, but it will be much more so on a Huge one. The downsides are that it's probably tricky to code and might be confusing to casual players.
2) Boost the amount of cultural defense the Kuriotates get in their cities. Fits nicely with the flavor (huge, sprawling cities that are legendary for being almost impossible to capture by any foreign invader) as well as the fact that they get added culture bonuses otherwise, too. This forces the invader to either spend more turns besieging the cities (giving the Kuriotate defenders more time to build defensive units) or build more siege weapons than actual city attackers. The downside is that I'm not sure if this actually has any real effect - cultural defenses are something that I usually just either bomb away in a couple of turns or downright ignore entirely.
But other than that this does look like a very, very nice civ now. I'm loving it already, just a bit worried if it'll keep up with the others.