Very interesting. I am from Latvia, and also a little bit more introverted than I would like to be. Nevertheless, 2 meters interval from each other in the bus stop is too much, I would prefer 1-1,5 meters :)
Is it rude to talk to strangers in Latvia? More often than no, because of the soviet past - then talkative strangers were often suspected be government agents. After the war, it was taught to every child: Don't you ever talk with strangers! Perhaps, this is why we now often cannot feel comfortable appraching complete strangers with probable cause :)
On the other hand, it is not so extreme than in Finland. If some stranger asks some Latvian native something, most probably they will receive a more or less respectful answer, though no too long.
I have a theory: the farther to the north, the more isolated are people, saving the communication for really close friends and neccessary situations. Where there is more sun, people are more open and friendly, at least at the first contact. On the other hand, ir seems that they lie more and with less effort in the south :)
RE: How you interact in Finland