Tthe dark side of the force is a pathway to many abilities some consider to be unnatural....
No idea how the inside mechanics work, but I guess you need to have high realtions and it should help a littel^^, although the big investment gains are where you can either get factories from all the majors or the balkan countries, so you should prioritise those, before you go and do the other ones, beware to have enough PP saved, because if you dont have enough PP the improve relation will stop and you are stuck below 80 (positive opinion).