totally 'd'accord' with all you said, rere...
pia is not the right one. she wasn't intelligent, she wasn't regal, she wasn't elegant and i don't really think they shared many interests, as guillaume seems to be a very shy boy who likes sport, reading, etc... and pia is like a tv star. however, i think they can maybe be dating. at least their relation was like that: an on and off relationship. maybe not now because they are on the summer break in the university, but i'm sure they were dating (or at least meeting) when they were in england.