You can only dissolve an empty duchy so generally that wouldn't work very often as most(all?) Duke's are also region lords.
Also, can't loot in your own realm.
...
Interestingly, there are more options to use against Dukes now than there were when I last had a ruler. Before a Duke could make it so none of his income was taxable by the crown. Granted, I think that the tax rate applies to all the Duchies but I could see certain rulers still using that power to great effect to harm those Dukes he or she doesn't like while having ways to appease the other Dukes.
I can think of other ways a realm can make things unpleasant for someone they can't ban. Bankers and Judges have ways of 'encouraging' those individuals that might be friendly to the offending individual.
Another realm could come loot it, however. Come to think, Morek wouldn't even need to declare war, it could just come down in BR and loot it rogue.
However, for the options listed Geronus, these don't really work when the guy is lord of the capital, and the capital happens to be a stronghold (which usually have food surpluses). Starving a region is also a hell of a lot more complicated now that the guy can simply go to another realm, receive tax in bonds, and use it to buy food.
However, the ruler could at least hike the ducal tax to a maximum, and manually give some back to the other duke(s). Similarly, everyone could drop a ton of militia in BR, right before taxes, and cause it to go bankrupt (loss of all infrastructure). Or simply to drain his financial resources.
Really sounds like you guys should have rebelled instead of protesting... Had you failed, I'm sure Morek could have forced you back in.
