i don't think it matters much how complex the economic model is so long as it gives realistic results, and you shield the player from it.
victoria:revolutions finally did that in the end, if you are liberal capitalist you don't have micromanage your development anymore (although you still have to fiddle with pops)
i am keen to see the military system reflect the unpredictable impact of technology, and particularly that having technology doesn't mean you will necessarily use it correctly. paradox does this in HOI with its 'doctrines' system
eg, the consistent influence of the 'bayonet' school of thinking which had such terrible effects for russia in the crimea, austria in 1866 and 1914 and france in 1870 and1914. and austria had a 'firepower' doctrine until 1859 when it seemed to fail against the french 'bayonet' system!
austria would have done much better in 1866 even with its minie-type lorenz muzzle loading rifles if it had used the sort of tactics usual in the american civil war (ie use of cover, entrenchment, artillery and reliance on rifle fire), even against the needlegun. austria had plenty of artillery. massed bayonet charges in column were exactly the wrong tactic. in 1866 benedek even studied von daun's 7YW tactics but just didn't seem to get it (daun's system relied on firepower, entrenchment and massed artillery and humbled frederick in the later stages of the 7YW and the war of the bavarian succession).
contrast with the ACW, where neither side started with a large standing army, or strong doctrinal preconceptions, except a bias towards the latest weaponry, and an open minded approach to employing it. the british also had a similar approach, arising from a keen awareness of manpower limits compared to other major powers.
over the period, you basically see the breakdown of massed or skirmishing musketry and rifle fire in the open, via entrenchment, to the development in 1917 by german and australian tacticians of modern multirole infantry squads (2 rifles, machine gun, light mortar) using cover to advance independently and flexibly (offensive tactics being the challenge)
a trope on military effectiveness that is usually cited in favour of the american, UK, french and prussian military, is the high level of education of the other ranks (NCOs and below) compared to say the austrian, italian, russian and ottoman armies, which placed them at a disadvantage as micro-level infantry tactics became more and more complicated. not being able to read, or read a map, and having multilingual units, are major problems in such an environment. compounded by conservative states' delusions of chivalry and valour (austria lost most of its junior officer corps in 1914)
i hope the boer war / WW1 ascendancy of defence over offense is well modelled. a few concealed boers with hunting rifles on a hill were capable of holding off whole brigades of british guards indefinately! well at least until nightfall. and the WW1 situation is well known. victoria, even victoria: revolutions, really fails badly in this respect
on politics, i think victoria underestimates the resistance of aristocratic conservatives; it is too easy to turn countries like austria, prussia, russia and turkey into liberal capitalist democracies. just the click of a button. you have to be able to try to move in that direction if you are russia or turkey, or prussia or austria, but it shouldn't be easy. even in france it was tumultous and took a long time, and in britain the aristocrats dominated until the 20thC. the russians had barely industrialised even by 1914. i recently read that russian capital and infrastructure investment between 1914 and 1917 far exceeded that of the entire preceeding century.
and finally, please keep up the good work on the graphics. Ageod's ACW is beautiful, and Napoleon's Campaigns screenshots look just as nice!