Well, most faction most endure heavy economic crisis at the beginning if you not try to blitz and burn everything... let me tell you, I salute with you to not blitzing, pillaging, raping, and enslaving even in your dire debt situation... but guess you don't disband most units you didn't need... actually if you want to play turtle, disband most cavalry except you are horse minded factions, because cavalry is the most exspensive unit that you may get. Second, use your infantry to garisson cities, and start disbanding them until bare minimum. Third, made peace with everyone, and start giving out trade rights, diplomat? it was must if you want not to blitz... fourth, try to improve roads first, and trade port second, and market later, except you have no sea trade port again... pumping out taxes may help, but watchout for unrest... and when you allready save a big ammount of money... built mines! it will bring most of your economy backbone immediately...