600 KILO BEAR,
I dont know how it is in whatever part of Europe you are in, but I have seen pictures of president bush’s wife, sarah palin and michelle obama wearing opend toed shoes. I really dont think they were “advertising themselves in public, if not for money in the form of at least a paid for date, then just for attention from guys.” (although i cant really prove that they werent, I do think it is still safe to say that this wasnt their intention).
As far as wearing sandals or opend toed shoes in a casual setting you yourself admit that it is not considerd grub and prust even in whatever part of the world you are in.