Can I change the country for an interview while applying for my F1 visa? My first interview was in Kyiv (Ukraine), I would like to reapply but the emergency interview in Ukraine is father than in Poland. I am half-Polish and I would like to change the country for the interview due to approaching date of my study.
You are allowed to apply in any embassy (US case). But according a consular officer, this is often not well interpreted, if you do not have good reason to do it. It could seems that you look for the less strict consular office (and if I read correctly your question, it seems that first interview was not so good, so ...). In addition the Polish embassy may have more problem to understand your school system, and to read/translate the documents.
So you can do it, but unless it is very unfavourable, I would try to get to Kiev.