Hi Henry,
Thanks for the response. There's no strict answer to the questions, as at this point I'm just exploring what's possible. As the most restrictive version, by non-Europe, I generally mean outside
bmi Zones 1 + 2 (, but I'd relax that to allow Armenia/Georgia/Turkey, and anywhere in Russia other than St Petersburg/Moscow. And by a visit, a proper "clear immigation / leave the airport" stop would be preferable, but I'm also curious what number of countries could be pased through if just touching down in the airport also counted.
Thanks.