As to dealing with 14th level PC's laying waste to a village, here are some thoughts:
- back in the wild west in the US there were bank robbers, some very successful. As they robbed more and more though, the reward size was increased. Eventually the reward would be high enough that bounty hunters would go after them. Basically, the more bad stuff you do, the more the general outrage is; the higher the outrage is, the more of a reward will be offered. If there is a 100,000gp (how does US$25 million convert into gp anyways?) bounty on your head, you're not going to be a happy adventurer.
- at some point in the indiscriminate killing, you're going to kill someone whom someone cares about. While that 19th level lord and his council of level 17s who rules the land won't deal with some random party rampaging his outer kingdoms, he quite possibly will drop everything if his son/daughter/wife got killed by said party.
Rewards don't have to be simple monetary rewards or vengeance either. For example, once could say: one of the mothers of a guy the pc's killed is childhood friends with someone high up in the assassin's guild. The assassin's guild is about to select a batch of assassin's into the inner circle anyways; the friend tells the mother, well, we needed some criteria to determine who gets initiated into the inner circle, we'll just put out a general proclaimation that whoever brings back the head of a PC will get automatic admittance. That way, you have people gunning for the PCs for their own selfish reasons, and you don't have to worry about shifting the geo-political power shifts if the PC's are able to defeat the NPC's coming after them, nor have a bounty for the PC's which may or may not be hard to believe.
etc etc