Fun quiz. But wouldn't São Tomé and Principe be the westernmost African country on the equator? Also, the tsar clue was used in the last quiz (word-for-word)!
The westernmost country that borders Russia -- in terms of where it shares a border with Russia -- is Poland. Since Russia has no territory west of Kaliningrad, I couldn't imagine anything else being the answer. Norway's border with Russia is east of Russia's border with Lithuania, Finland, Belarus, Estonia, and Latvia, so I tried those, too. I assume Norway counts because its westernmost post is the farthest west of all countries that share a border with Russia, but the question didn't make it clear that that was the criteria. For my money, there are six better answers than Norway.
2) Which one is “westernmost”?
Voila