knonfonda,
Just a couple of a suggestions if your playing historically. Greek cities and other so called 'civilized' cities, as a rule of thumb, should just be occupied and NOT enslaved and exterminated (although the were exceptions, the romans only exterminated cities like corinth and carthage due to mitigating circumstances and of course there may be your own versions of these in your game, its a history taking a different path after all). The republic as a whole felt it was extending its ideas of law and order to defeated nations and so exterminating the hellenistic world wouldnt coincide with that. On top of that, not exterminating these cities means higher population which meant more people to tax and would fit in nicely with roleplaying of the spread of the
publicani throughout the provinces of Asia and Spain, as the roman business class and aristocrats didnt want to kill the goose that was laying such splendid golden eggs so to speak.
Of course by all means play as it suits you as enjoying the game is most important thing but im trying to play historically as well and to be honest just occupying cities shouldnt cause to many problems with rebellion if you plan ahead. If your attacking a foreign power, i usually take several armies (this is obviosuly easier the more wealth you have so you may struggle a little at 230 B.C. or not depending on how many wars your involved in) and thus i have reinforcements for my consuls army (which is the only full stack i usually attack with, although i may occasionally use smaller half stacks elsewhere in the war led by a legate or tribune as was fairly common) but also it provides plentiful garrison forces to be used in conjunction with either a higher influence level governor or a level 4 government type with a client ruler, which will only take 3 turns to set up (1 for pacification,1 for type iv gov, 1 for a client ruler) and shouldnt slow down your war effort. When the client ruler dies, if you use one, feel free to move in your own governor and change the government type, which again simulates how the romans gradualy absorbed many provinces.
As others have pointed out, "barbarian" cities are more fair game for enslavement or extermination and also that dealing with rebellion in occupied cities was part and parcel of Roman history. It may not be the most simple way to conquer your way to victory, but it has a more historical flavour to it which makes it more fun i think. As i said though, mix it up a little to keep your interest, I do. An example would be if my consul was selfish and say hated Greeks i would feel i would have justification to enslave or exterminate a greek city if i wished rather stick to the house rules ive set myself.
You seem to have good grasp of playing historically anyway

and im largely echoing what some posters have said so i doubt what ive said above will change your game approach to much, but it may help justify your playing style to yourself or give your a pointer or two.
nhartwell