About the sieges...for the next version...I will tell you same I told Shimmler for the ASoIaF stimulation of the Siege of King's Landing:
In standard Mount and Blade,you can pass 3 phases of siege:Walls,Streets and Keep Interior.This was deleted in Warband.
You can use this old system to make unique,multi-phased sieges.For example,let's take Minas Tirith:
Level 1(Catapults or Ram)
Level 2(Ram)
Level 3(Ram)
Level 4(Ram)
Level 5(Ram)
Level 6(Ram)
Level 7(Fountain:Ram)
Citadel(Interior:Ram)
Every level has an unique garrison.Level 1,2,3,4,5,6, have x swordsmen and x archers each.Level 1 is also protected by lord's troops like normal siege.
Level 7 has x fountain guards and y best archers.The defense is led by Beregond,which is a npc appearing only in lv7 siege.
Citadel is protected by citadel guards and citadel knights and best archers.