1. I would like to learn English, because this language is spoken in many countries, and it is a lot easier to travel when you know this language.
2. The main diffuclty is the langauge barrier, I am a shy person, so it is quite hard for me to start a conversation, especially in another language.
3. The main reason why peole don't progress in their studies is because they don't have a strong motivation and someone to practice the language with. Having conversations with a native speaker can help you improve really fast.
4. I don't think there is a danger, as I love my first langauge so much, that no other language will ever replace it
:)