Remove the fog of war with a console command. Bring up the console with the ` or ~ key. type in "toggle_fow".

Force Diplomacy is a mod, it's on the first page of the Unofficial Mods sub-forum.

You give a province away, along with money through the diplomacy screen. You can also give factions money directly through the console (which then doesn't give you a benefit in terms of relations). The command is "give_money [factionname], [value of mnai]". You can give negative money to sap their treasury as well.