I'll let you guys in on a cheat, or rather an exploit, I discovered. When you get a promotion decline it and wait another 10 years for the next one, in the mean time raise your own wage to whatever your city economy can handle. By the time your offered a promotion again you should have an enormous personal fortune, the thing is you get to keep it and when you choose your new province you'll be able to donate your entire fortune to your city.
Using this exploit I nearly finished the campaign at the hardest settings, I think I won over 20 provinces.
Also, I belive pressing "A" will speeds the game up, it'll make those 10 years pass ALOT faster.