Basicly, being a regent sucks. At best, you can pilfer some cash from your leige. At worst, the little brat kills you by shoving you off a balcony. Countries that are ruled by a four year old aren't showing the instability that should be the bane of every house and kingdom.
This shouldn't be the case. Being the regent should be the same as being de-facto king or ruler, able to rasie levies and collect the taxes from the child's demense (with a malus depending on traits, because a content or honest regent would'nt want the cash, while a greedy or deceitful regent might want even more). As a result, the position of regent should be contested bitterly by the most powerful nobles of the realm, not some lowborn ,weak regents being quickly turfed out and lords coming to battle over who looks after their leige until he is of age.
There should also be a bonus for being guardian as well as regent to the underage ruler, as this would translate to a very close relationship between the regent and the child, and so a regent and guardian should be nigh impossible to push out of power. That is, if the child and the guardian have a good relationship.
Some more events would be nice as well, for example having nobles rally to the banner of the underaged king to depose a tyrannical regent, with the king's defeat leading him to be imprisoned and the regent reign in his stead. Edward III is a great source for things like this.
Thoughts?