I'm regent for my king, now what?
You don't get any powers or any decision to carry out any of those things.
However there are events for all of those which can be triggered depending on a number of factors and sheer dumb luck. At the same time, your charge can get the event to charge at you with a wooden horse and kill you by pushing you off the balcony.
You can find the full list of events here. You can then proceed to looking them up in the events file and find the triggering conditions for each one of them.