as the ERE i find it more easy to put up with the council when you start out with Thrace, gather more power via Varangian guard and Grabbing the duchy of Nikea, fiddling with obligations to increase taxes and go do a city building spree in my demense, pump up levy buildings and retinue, eat the EREs dejure lands, and after you have a 7k+ pike retinue you can buy favors to force the council to abolish war decs and council empowerment for the +2 demense and watch the vassals cower at the 20k+ troop power you personaly control, which will only grow as your realm size grows and you build more retinues, and tech grows and you build more levy in your countys, along with decent military/diplo stats for your rulers and heirs.
i hate relying on stewardship for demense sizes because factors out of your control can gurantee that your next heir wont be able to have the same demense bonuses from stewardship, i prefer to educate for Military/Diplo stats along with the foci for my ruler, War focus got even better with the new events to get commander traits AND teach them to your commanders, they fire pretty frequently and this along with military education makes your rulers/heirs strong commanders with good sized personal levy, and you patch up and boost your diplo with the other Foci, and as the ERE you have a massive opinion factory with Viceroys. council rebels after you establish your military power are merely a nusance unless your unfortunate enough to lose too many levy/retinue in a war and they get clever, but five years later you can use your massive treasury to favor the council back into abolishment, and you can build a large number of kids to keep your large viceroys into NAPS, its not like you have much better to do with them since most of your neighbors are terrible allys since they have land that belongs to Rome and your going to want to conquer them regardless, at best your closest possible allys are going to be the nomads in the steppe, since most nomadic land wont be of interest to you outside of the Crimea.
you dont want to create Greece (or Italy if you plan on moving capitals) because you want the area of your capital kingdom to have more duke viceroys that you can tax, along with avoiding the quirks of Born in the Purple inheritance. everything else gets stuffed under king vassals. early game you dont want to create anatolia either, only when the vassal limit becomes a concern you start consolidating vassals under king viceroys.
and as the ERE you can easly sit at 7-8 demense which lets you hold Thrake and Nikea + a barony in Constaninople, the latter you can give up if you want to hold the county of Rome later for RP, but Thrake/Nikea is one of the richest Demense combos in the game, six out of seven countys are all costal and you can stack a ton of citys in them for a huge amount of income. with abolished council you can add in two to three more countys, the two county duchy west of thrake is good for this, but you have to demolish a ducal title to avoid opinion penaltys, or you can fit in Latium if you wanan RP holding rome, but i reccomend keeping Thrake/Nikea because building up an italian demense will be a huge pain and it will weaken you to switch there too early. plus Constantiople has the Theodesian walls.