Tolerance

1. What tools can we use to stay tolerant and be empathic and open-minded?

First of all, I think you must not to pigeonhole somebody. Because when you do this you have a picture of somebody that is maybe not the right one.
You should meet somebody in a neutral position and after that you should make an opinion about this person. I think this is the ideal way to be open-minded.
But I mean not, that you have to accept all things which you hear, see, etc. it’s important to understand it and to be open for other cultures, countries, etc.

Then, you shouldn’t believe all things what people say. You should make your own picture about something and somebody.
I think it can help you to be tolerant when you go to other countries and meet persons from other cultures. (Maybe) only than you can understand some things. 

2. What kinds of questions can you ask in order to reach understanding of a known-unknown situation?

I think it’s important to ask open-ended questions and not closed-ended questions. Only with the open-ended questions you have an answer with contents. In that way you can learn more something about the person or the culture.
Secondly, if you are interested in something or somebody you shouldn’t be shy. It’s important to ask this person and don’t think that it could be a stupid question.