When the film was being made, the Suez crisis was less than six years ago and naturally, the Egyptian government wouldn't let a film on such a still very sensitive subject be shot by a British film company in Port Said. So Mackendick shot the Port Said scenes in Mombasa instead.
I think that the Syrian's scenes with Sammy should have been left in, because it would have shown that the dangers Sammy faced on his long trek were from more than lions and snakes. Besides, by today's standards, the attempted seduction scenes would probably have been more hinted at than explicit.
I think that Mackendrick was going all out for realism in this picture and we can only guess how it would have turned out had he been given a free hand by Balcon to make it as he wanted to.