Yes, winter isn't a time for shopska salad, but rather for cabbage sarmas and turshiya. Though I don't really enjoy these.
The cold water thing applies only to old people, I think. Young ones don't usually care. I prefer cold water even in winter. But if you're cold, then it really is easier to get sick. That's why I pity the girls who go bare-waisted even in cold days, because "it's cool and fashionable", ruining their kidneys and what not.
And as for the metro tickets, it never really occurred to me that the slots should be on the right. I just switch hands and insert it with the left. At the same time I use the right one to put my wallet away or something.