Open your launcher and put all the settings you want in there, like Hi resolution textures or bloom or whatever you want, then hit save and close the launcher. Then go to your steam and right click rome total war hit properties go to set launch options and then type in -mod:play_Rome -show_err -nm with a space in front of the -mod. Then launch the game through steam and it will allow you to play the roman campaign. Also make sure all of the mod is in the Rome Total War Folder in the Steam Program 86x files area for RTW.