I actually really like this idea - we need more reasons to visit ports and pick up "Side missions". Escorts, Deliveries, BountyHunts, Posted rumors (i.e. what ports was so and so last seen at?), Political transports. Land Raider inserts, Spies....
There is so much that can be done to free a player from only combat and crafting.
Why would the Bounty need to be posted at capital though? I'd say let it be posted at any Freetown or Regional capital - Freetowns would allow all nations to see the post and besides... Charlston is rapidly becomming quite removed from any pvp battles as the US conquests southward.