well fog is possible but i dont kno how to get it in only one spot and smoke i think is possible but i dont think constant smoke is
it will probably go away if possible or it will be an exception if u get it from another map like u sed
hmmm.....u'd need to import some emitter scenery and place it, then edit smoke color and spread. good luck fighting off exceptions(emitters are kinda touchy, except infinity's beam emitters.)