Ali, I don't think the titles would be a problem, because you can't copyright a title. But with the scenes... In theory there wouldn't be, because you can't copyright an idea, only the expression of it, i.e. the words. But also perhaps what people do and how would count? If you lifted whole scenes from another novel, even if you changed the names and tweaked the dialogue it would still be plagiarism. I suspect (and I'm no expert) it's a very grey area, as Dan Brown and the Holy Blood/Holy Grail lot would tell you.
I think that the fact that you acknowledge it isn't really the point: either you're using someone else's copyright material, or you're not. The best people to advise you would be the Society of Authors, who have very good leaflets on this kind of thing, and will also answer queries on the phone.
Society of Authors Publications
Emma