[Lalaith]

Yes, I agree - for the Rohirrim to look down on the Dunlendings, or for the Elves to look down on Men, has nothing to do with class and everything to do with cultural/racial prejudices...
Hobbit society seems to me to be a slightly more egalitarian version of the class systems of early 20th century rural England.

Elrond and his family, and Galadriel and her family, were presumably considered 'grander' than the ordinary elves who populated Rivendell and Lorien. I also get the feeling that the Calaquendi looked down on the Moriquendi and that the folk of Thranduil were a bit more rustic and less grand than the Galadhrim or the cosmopolitans of Rivendell.

Gondorian society was more class-ridden, I feel, than that of Rohan. The Anglo-Saxons were much more egalitarian than the Normans that conquered them, and I think there is a correlation.

Tolkien himself was certainly not an aristocrat. His father was a bank manager (middle-middle) and his grandparents were shopkeepers (lower-middle).
Tolkien himself though, as an academic, would qualify as upper-middle, so there's a bit of British social mobility for you...

(PS - Remains of the Day was actually written by a Japanese author, Kazuo Ishiguro....and if you want really complex class systems, all you have to do is read To Kill a Mockingbird....small town Alabama....)