In regards to your questions about Durham and Warwick, I will address the location issues and types of students you will find in both.
Durham
+ves
The location is not that bad. It is a campus and collegiate environment, in a university with nice historic architecture. Outside the campus, there will not be much to do in Durham town[-stroke-village] itself, but you will have easy access by train and bus to the bigger Newcastle.
The students there would be bright and polished. I am not aware of them being overtly conservative.
-ves
Newcastle is really your only hope of fun outside campus. There are really no other cities close by to write home about. Leeds is a bit far away. It is also located in the most Northern of North East, which are areas of low income and low academic achievements. Your night outs might involve mixing with far less enlightened and polished people, if it is not a university students-only venue. Some late night issues are soughted out with the fists under the influence of a lot of alcohol and boredom (more than other regions of the UK). The police are good though and always in the vicinity, so should not be too much of a problem.
Durham students perfectly exemplify what is called the “rah-rah” kids more than any other university outside Oxbridge.
http://www.urbandictionary.com/define.php?term=rah-rah
Rah-rah kids are not necessarily, and are not usually, part of the aristocracy. They are mostly kids of the aspirational upper middleclass parents and people with wealth started less then 2 generations earlier.
Don’t be surprised to find some cliques of students who know each other from their private high school and are not as open to those outside their clique (especially those who might not be private-school educated). Their self-assurance (and maybe pretentiousness) might come off as “snobbish”.
Warwick
+ves
Warwick is another campus university in a much bigger city and it is not collegiate. Coventry is more interesting than Durham and almost a twin city to Birmingham (which itself is far more interesting than Newcastle). You will have much easier, quicker and frequent access to transportation to Birmingham than from Durham to Newcastle.
Better still, you are closer to London and at least another 2 cities (Leicester and Nottingham, maybe you can even add Milton Keynes).
You will also have an opportunity to mix with more students from other universities. Birmingham alone has over 4 universities and Coventry has University of Coventry. So a bigger mix of student population to mix with, which can only be rivalled in the UK by a university in London.
The students at Warwick will also be bright and polished. Also far less rah-rah than Durham.
-ves
Warwick’s architecture is contemporary and modern. (If you are the type to see this as a negative)
Many of the kids there can be quite insecure. They might have just found out [too late] that the reputation of Warwick might not be what they were sold when they were applying to university and you will see many trying to convince themselves that they are the next tier to Oxbridge despite the university not having sufficient history, recognition and achievements to lay claim to such.