No, when I took Brest back, there was no resistance, since the city had only been in Scandinavian hands for a very short time and they didn't manage to pump any culture in it at all.
As for the file, Beyond the Sword/Mods/Rhye's and Fall of Civilization/Rhye's and Fall of Civilization.ini. Change the 1 in NoCustomScenario = 1 to 0, it will allow you to choose single player -> custom scenario (and then select one of the two RFC scenarios) from the menu. Some of these options will case the mod to crash, but the random seed one will work fine.