Murphy was doing movies like beverly hills cop, trading places(one of my all time favs) and 48 hours at the time, movies which still stand up today so i think its fair to say he would have added much to ghostbusters.
As for belushi i actually think he would have been awesome in ghostbusters. He's got such dead pan lines in blues brothers and played so well off aykroyd in that movie i think its a shame he wasn't in it with dan again. But then we're all so used to seeing murray in it we can't imagine what it would be like without him in it.
As for belushi i actually think he would have been awesome in ghostbusters. He's got such dead pan lines in blues brothers and played so well off aykroyd in that movie i think its a shame he wasn't in it with dan again. But then we're all so used to seeing murray in it we can't imagine what it would be like without him in it.