These are my thoughts. This is going to be a long reply.
Ok. Fundamentally, what was the Ottoman Empire? The Ottoman Empire was an Islamic state ruled by a Turkish dynasty which treated the Balkan peninsula of Europe as its geopolitical focal point (moving its capital to Europe by 1365), and which eventually came to portray itself as an Islamic incarnation of the Roman Empire based in the areas associated with the "Byzantine" Empire (perceived straightforwardly as the Roman state by the Ottomans and others). The "territorial core" of the Ottoman state should be considered the area which once was the Byzantine core, immediately flanking both sides of the same capital city -- in the case of such a large state as that governed by the Ottomans, we can say that its
geopolitical "true core" would be the Turkish provinces of Asia Minor along with essentially the entirety of the Balkans south of the Danube and Sava Rivers (but not including the Dalmatian coast). To keep it simple, we could just say that the geopolitical core of the Ottoman Empire were those areas conceived as "Rum" and "Rumelia." The Ottomans expanded far beyond these areas of course, but everything beyond those areas was either a rather temporary gain and not a long-term Ottoman territory (in Europe: advances north of the mentioned rivers into Hungary, or attempts to take the Dalmatian coast), or encompassing territory which was of some distance from the capital and subject to a less direct rule and economic attention (this would include essentially all of the mostly Sunni Muslim areas that were held by the Ottomans outside the Balkans and Asia Minor, ie in the Arabian peninsula and North Africa and elsewhere).
ConjurerDragon brings up, I think, some very interesting points regarding the millet system and Ottoman taxation. So, yes -- the Christians in the Ottoman empire were subjected to more onerous tax policies than Muslims. Ok, what is the right way to represent that? I think a problem to consider is that the specific Islamic law millet system imposed by the Ottomans over the Balkans is, in economic organization terms, actually very different than the feudalism occurring at the same time western Europe (and the systems that developed out of that). On some of the complexities and nuances of Ottoman taxation, see
http://digitalcommons.uconn.edu/cgi/viewcontent.cgi?article=1117&context=econ_wpapers This is somewhat tangly to try to describe -- to illustrate a point, let's hypothetically posit for just a moment that the meaning of the millet system implies that the Ottoman Empire
should receive higher tax amounts from Christian provinces than from Muslim ones. At least one problem with that framing would be that the basic mechanics of our game wouldn't even really allow that as possible: that is, provinces of a non-state religion automatically suffer an income decrease compared to those of the state religion.
So is our basic game engine therefore fundamentally wrong toward portraying something like the Ottoman state? Actually, I think not really. That is, so then, abstractly, I think this is a way to conceive the Ottoman system over the Balkans: the Ottoman
Empire was practicing, through its millet system, a unique economic system which can be actually thought of as a form of
imperialism -- I use the term
imperialism in a rather specific and technical economic sense, essentially the Marxian or World Systems/Dependency Theory sense, which would indicate the economic enrichment of a "metropolitan" core being dependent on the economic exploitation of a "periphery," with the relationship between those accomplished through complex socio-financial mechanisms.
Ok, this seems to be the best place to bring up my brief thoughts now also on Venice and other Latin states ruling provinces in the Balkans: We should also note the identification by some economists of Venice, during the early time period represented in this game, as essentially being the first complex modern "imperial" state (on that, Karl Marx himself
charted the history of actual direct movement of the "base" of the largest capital accumulations in a straight line through history as a succession from medieval Venice to Amsterdam to London to New York; and note that important US/European banking families such as
the Warburgs originally began as bankers in Venice during the early period of our game's timespan). The Venetian Republic as a finance empire had a metropolitan core at Venice which was dependent on its maritime empire of colonies (and I think at present the colonial/dependence relationship is represented well -- ie, Venice as a CoT closes and moves to Vienna after the Ottomans capture Crete, as the the financial metropolis of in Venice only maintains itself through dependence on its significant colonial empire in eastern Mediterranean Greek provinces).
Ok, since I'm on this subject, just to bring this up now: I noticed on the latest update that Venice begins only with the Venetian culture -- searching through the events, I can see one in which it loses the Greek culture, but not one in which it's ever gained, so I'm guessing that this means Venice never accepts the Greek culture at this version of the mod. I think this is an interesting and actually definitely appropriate choice. I disagree with removing Dalmatian culture from Venice however (I think this a good description of how well the Dalmatian coast integrated as a part of the Venetian Republic:
http://en.wikipedia.org/wiki/Dalmatian_Italians#Republic_of_Venice_.281420_-_1796.29). Also, I think I may have been misunderstood earlier when I discussed the Latin states not receiving Greek culture: what I specifically meant was that Epirus, Achaia, and Athens should not accept Greek culture. I think this is more historical as the Latin knights and nobility were seen by the Greeks as invaders and subjugators, and in gameplay terms this would also improve matters by making these states especially weak so that the Ottomans can topple them rapidly when the time is correct for that to occur. Weakening the Latin states of Greece also corrects a problem I have noted in that sometimes Athens, Epirus, etc will form alliances with other states who then declare war on TUR and actually in that context provide quite a challenge -- ie, in the present game representation, these states are too strong.
Back to the main issue: the notion that the Ottoman Empire was some sort of modern wonderland of multiculturalism is essentially the most extremely rosey and sympathetic interpretation possible. There are a range of interpretations on these matters among historians, and it's good to note this range of interpretations. We should also note that there are Turkish political figures today who describe the Ottoman history in such terms (the present foreign minister of Turkey, Ahmet Davutoglu, has very poetically described the Balkans as achieving a unique golden age under Turkish rule). But that's far from the only interpretation.
Just as a quick display of a point of view on the other extreme, reading through this book a bit would entail viewing a sort of classic example of the negative framing of Ottoman conquest and rule over specifically the Greeks:
http://books.google.com/books?id=kg5CAAAAcAAJ&pg=PA1
Also:
http://www.srpska-mreza.com/bookstore/kosovo/kosovo3.htm
So, another interpretation is that the Ottomans essentially economically destroyed the Christian areas of the Balkans in a long-term sense, and even committed a sort of near-genocide during the process of conquering those areas, and that after the conquest many people either fled Ottoman oppression by hiding in the mountains, and Ottoman control of those areas was never effective or efficient.
Here's my view: the Ottoman Empire rule over the Balkans was based on a systematic impoverishment of Christian areas, on which a relative economic prosperity of Muslim areas was based. Even if sometime the actual tax rates imposed on Christians were higher than those imposed on Muslims, the Ottoman taxation system itself and overall system of government prevented real economic development from occurring in the Christian areas. Because of the effects of the Ottoman system in economically depressing the Christian provinces, I do not think we should interpret the jizya in such a way that increases tax revenues from the Christian areas -- rather, these areas were exploited and held down in such a way that economic growth therein was stifled, and overall tax revenues should be portrayed as, over time, lower as a result.
On whether TUR should have manpower to build up armies within its border provinces, consider in the recent link posted by ConjurerDragon:
The central role of the sultan affected Ottoman military practice. By tradition, the sultan assembled one large army in Istanbul and then marched to the frontier to make war. After 1550 the sheer size of the country created geographic limitations on further growth. The army could only travel 90 to 100 days' march before it had to turn back in order to get home before winter. In 1529, the siege of Vienna could not begin until September 27 and had to be called off on October 15 to allow time for the return journey. Even if later sultans had been good generals, the size of the country limited their options. Regional armies, close to the borders, could have solved this problem, but decentralization ran counter to the dynastic principle. Once decline began, regional armies became risky centripetal forces.
So, really, a more historical framing is for the Ottomans to be forced to build up large armies near Istanbul, and for inability to build large armies in border provinces to limit Ottoman expansion.
I have a few other thoughts on gameplay representations of the Ottoman Empire, and will try to post again later today on those subjects.