... The player who has the majority of ownership for a section of map terrain should have the ability to rename the location for everyone in the game. ...
Still not sure I'll care for multiplayer, but if I did, I'd still want some ability to maintain the map coordinates & location names separately somehow. I'm thinking of things like "Istanbul's not Constantinople any more" and the Falklands/Malvinas, Malvinas/Falklands argument (still evident in the Wikipedia redirect).
Multiplayer can be amazing fun... just don't have your first multiplayer experience with strangers on the internet. Many strangers on the internet will either try cheating, quit when they start losing or possibly have a rude immature personality.... which can really destroy the fun. First do multiplayer with friends and/or family when possible and start as a team against AI opponents. If you must start with multiplayer online make sure you know the personality and behaviors of the individuals within the game... typically online guilds have members who all trust each other and play together.
In regards to having map location names separately... this can cause confusion between the different players. As you might have named a location as "The Great Forest" while another player has it called the "The Grey Forest". Ideally the names for all map locations should be the same for all players so communications with terrains are not confusing.
I really dig your idea, NT. The only issue I have is on really huge maps. You will have alot of wild space like mountains/forests/oceans (at least I hope...I want to avoid Civ4 tile spam). There could definitely be an instance where no single player has territorial boundaries in a certain area.
How do we address this?
Yes, I'm expecting many areas which are not owned by anyone for large, huge, and gigantic maps. I'm not sure if exploration would be fair... as one nation playing a turtle strategy would lose naming rights to another player using an expansion blitz strategy. The best fair way to have these wild spaces named would be allowing all players to vote. One player submits a name change request and the other players can choose none or submit their own name change request. The next turn each player gets to vote among the list of names. If 4 different human players all want different names then it should randomly choose one of the 4 names.
However an area gets named (exploration, ownership, other) I think that once a feature is named the name should stick for the duration of the game in multiplayer. I dunno I guess I can see both advantages and disadvantages to renaming stuff, it just seems like especially a hotly contested area it could get old for it to be renamed many times. Also, what if empire boundaries divide a geographical feature among 2 or more empires?
The actual renamings of locations should only happen once every 20_turns OR if the location falls under control of a new empire. I say 20_turns because an event may change the terrain such as a volcanic eruption leveling a forest or a great battle may cause a swamp to earn a new name. If two players are renaming one location often due to the change of control the other players can pressure via diplomacy one or both players for a specific name to remain.
I estimate it would be very rare for two empire boundaries to perfectly share (50% and 50%) one single geographical location... but for such an unlikely scenario the player who originally obtained the majority should have naming rights.