Totally agree with last poster on how key aggression is in TW games. Rather than sitting around and thinking about taking rebel regions with 8+ units like Kiev, thinking about smashing your neighbors. Nearby factions are weak initially and can hurt you later on while rebels just sit there. There is absolutely no reason to be cash strapped when you are near both Byzantines and Venetians (two of the richest factions around). The only limiting factor is how fast your armies can march.