It seems that North Americans struggle with the word, but most Europeans (including Brits) don't. Don't know enough about linguistics to guess why!

Try saying "Twix" the way you'd imagine a German or Scandinavian accent to sound.

Yes, definitely!!

I think it wasn't clear whether you were supposed to say "tee-vix" or /tvɪks/.

For non-Russians, try and figure out which of the above two is right. No one help them, because you'll be taking away a learning opportunity. https://www.youtube.com/watch?v=9hNphbAm_Hs