I didn't vote at all in round 1, but in round 2 I voted for #4 based on the map-maker's stated intent to work on a theme. If there will not be a theme, then hopefully this will become clear before voting ends so I can change my vote to #1.
Also, I finally figured out what it is I don't like about #2. The pirate theme is cool, but the problem is that the theme doesn't fit the gameplay. The Centerscape map is almost purely classic gameplay, with no gimmicks except a single one-way attack. It really seems pointless to have a theme that includes both land and sea combat and fleets of ships holding influence in different parts of the sea if there's nothing to it except normal attacks and continent bonuses. It seems like different ships should have different special attacks, similar to the Waterloo map. There could also be special bonuses for things like hidden treasures and important ports.
Besides that, this particular map really needs a fantasy theme, and the pirate thing doesn't really fit.
Anyway, I guess major gameplay changes would probably go against map-maker #2's original intent, but I just don't see a reason to play on a pirate map that doesn't have matching gameplay.