well good luck for the bsms application.
i dont know how the medschool inter-uni thing works. the people i know spent their first year at exeter, then there second in plymouth, then i *think* they went back to exeter with the view of some going to cornwall for fieldwork.
exeter is mixed - full of stereotypical oxbridge types, but some students have exeter as their first choice whilst others have it as a backup if they dont get into oxbridge. it has the same feel as bristol and to some extent oxford in terms of student make - white, well-off, middle-class. the postgrad community is far more diverse, the uk postgrads tend to be from the usual "top 25" unis (i know a few from oxford, lse, imperial and ucl but never cambridge funnily enough...). exeter simply attracts uk students from a particular cultural background, more so than many other universities (i think tradition and location plays a big part here, more than perceived quality) - london, bristol, exeter, oxford, cambridge, st andrews, durham (and no doubt a scattering of others) make up the usual suspects (statistics show this too) and i think because of this, its perceived as an oxbridge reject uni at times.